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linux-zen-desktop/arch/powerpc/kvm/book3s_xive.c

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Initial commit
2023-08-30 17:31:07 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2017 Benjamin Herrenschmidt, IBM Corporation.
*/
#define pr_fmt(fmt) "xive-kvm: " fmt
#include <linux/kernel.h>
#include <linux/kvm_host.h>
#include <linux/err.h>
#include <linux/gfp.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/percpu.h>
#include <linux/cpumask.h>
#include <linux/uaccess.h>
#include <linux/irqdomain.h>
#include <asm/kvm_book3s.h>
#include <asm/kvm_ppc.h>
#include <asm/hvcall.h>
#include <asm/xics.h>
#include <asm/xive.h>
#include <asm/xive-regs.h>
#include <asm/debug.h>
#include <asm/time.h>
#include <asm/opal.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include "book3s_xive.h"
#define __x_eoi_page(xd) ((void __iomem *)((xd)->eoi_mmio))
#define __x_trig_page(xd) ((void __iomem *)((xd)->trig_mmio))
/* Dummy interrupt used when taking interrupts out of a queue in H_CPPR */
#define XICS_DUMMY 1
static void xive_vm_ack_pending(struct kvmppc_xive_vcpu *xc)
{
u8 cppr;
u16 ack;
/*
* Ensure any previous store to CPPR is ordered vs.
* the subsequent loads from PIPR or ACK.
*/
eieio();
/* Perform the acknowledge OS to register cycle. */
ack = be16_to_cpu(__raw_readw(xive_tima + TM_SPC_ACK_OS_REG));
/* Synchronize subsequent queue accesses */
mb();
/* XXX Check grouping level */
/* Anything ? */
if (!((ack >> 8) & TM_QW1_NSR_EO))
return;
/* Grab CPPR of the most favored pending interrupt */
cppr = ack & 0xff;
if (cppr < 8)
xc->pending |= 1 << cppr;
/* Check consistency */
if (cppr >= xc->hw_cppr)
pr_warn("KVM-XIVE: CPU %d odd ack CPPR, got %d at %d\n",
smp_processor_id(), cppr, xc->hw_cppr);
/*
* Update our image of the HW CPPR. We don't yet modify
* xc->cppr, this will be done as we scan for interrupts
* in the queues.
*/
xc->hw_cppr = cppr;
}
static u8 xive_vm_esb_load(struct xive_irq_data *xd, u32 offset)
{
u64 val;
if (offset == XIVE_ESB_SET_PQ_10 && xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
offset |= XIVE_ESB_LD_ST_MO;
val = __raw_readq(__x_eoi_page(xd) + offset);
#ifdef __LITTLE_ENDIAN__
val >>= 64-8;
#endif
return (u8)val;
}
static void xive_vm_source_eoi(u32 hw_irq, struct xive_irq_data *xd)
{
/* If the XIVE supports the new "store EOI facility, use it */
if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
__raw_writeq(0, __x_eoi_page(xd) + XIVE_ESB_STORE_EOI);
else if (xd->flags & XIVE_IRQ_FLAG_LSI) {
/*
* For LSIs the HW EOI cycle is used rather than PQ bits,
* as they are automatically re-triggred in HW when still
* pending.
*/
__raw_readq(__x_eoi_page(xd) + XIVE_ESB_LOAD_EOI);
} else {
uint64_t eoi_val;
/*
* Otherwise for EOI, we use the special MMIO that does
* a clear of both P and Q and returns the old Q,
* except for LSIs where we use the "EOI cycle" special
* load.
*
* This allows us to then do a re-trigger if Q was set
* rather than synthetizing an interrupt in software
*/
eoi_val = xive_vm_esb_load(xd, XIVE_ESB_SET_PQ_00);
/* Re-trigger if needed */
if ((eoi_val & 1) && __x_trig_page(xd))
__raw_writeq(0, __x_trig_page(xd));
}
}
enum {
scan_fetch,
scan_poll,
scan_eoi,
};
static u32 xive_vm_scan_interrupts(struct kvmppc_xive_vcpu *xc,
u8 pending, int scan_type)
{
u32 hirq = 0;
u8 prio = 0xff;
/* Find highest pending priority */
while ((xc->mfrr != 0xff || pending != 0) && hirq == 0) {
struct xive_q *q;
u32 idx, toggle;
__be32 *qpage;
/*
* If pending is 0 this will return 0xff which is what
* we want
*/
prio = ffs(pending) - 1;
/* Don't scan past the guest cppr */
if (prio >= xc->cppr || prio > 7) {
if (xc->mfrr < xc->cppr) {
prio = xc->mfrr;
hirq = XICS_IPI;
}
break;
}
/* Grab queue and pointers */
q = &xc->queues[prio];
idx = q->idx;
toggle = q->toggle;
/*
* Snapshot the queue page. The test further down for EOI
* must use the same "copy" that was used by __xive_read_eq
* since qpage can be set concurrently and we don't want
* to miss an EOI.
*/
qpage = READ_ONCE(q->qpage);
skip_ipi:
/*
* Try to fetch from the queue. Will return 0 for a
* non-queueing priority (ie, qpage = 0).
*/
hirq = __xive_read_eq(qpage, q->msk, &idx, &toggle);
/*
* If this was a signal for an MFFR change done by
* H_IPI we skip it. Additionally, if we were fetching
* we EOI it now, thus re-enabling reception of a new
* such signal.
*
* We also need to do that if prio is 0 and we had no
* page for the queue. In this case, we have non-queued
* IPI that needs to be EOId.
*
* This is safe because if we have another pending MFRR
* change that wasn't observed above, the Q bit will have
* been set and another occurrence of the IPI will trigger.
*/
if (hirq == XICS_IPI || (prio == 0 && !qpage)) {
if (scan_type == scan_fetch) {
xive_vm_source_eoi(xc->vp_ipi,
&xc->vp_ipi_data);
q->idx = idx;
q->toggle = toggle;
}
/* Loop back on same queue with updated idx/toggle */
WARN_ON(hirq && hirq != XICS_IPI);
if (hirq)
goto skip_ipi;
}
/* If it's the dummy interrupt, continue searching */
if (hirq == XICS_DUMMY)
goto skip_ipi;
/* Clear the pending bit if the queue is now empty */
if (!hirq) {
pending &= ~(1 << prio);
/*
* Check if the queue count needs adjusting due to
* interrupts being moved away.
*/
if (atomic_read(&q->pending_count)) {
int p = atomic_xchg(&q->pending_count, 0);
if (p) {
WARN_ON(p > atomic_read(&q->count));
atomic_sub(p, &q->count);
}
}
}
/*
* If the most favoured prio we found pending is less
* favored (or equal) than a pending IPI, we return
* the IPI instead.
*/
if (prio >= xc->mfrr && xc->mfrr < xc->cppr) {
prio = xc->mfrr;
hirq = XICS_IPI;
break;
}
/* If fetching, update queue pointers */
if (scan_type == scan_fetch) {
q->idx = idx;
q->toggle = toggle;
}
}
/* If we are just taking a "peek", do nothing else */
if (scan_type == scan_poll)
return hirq;
/* Update the pending bits */
xc->pending = pending;
/*
* If this is an EOI that's it, no CPPR adjustment done here,
* all we needed was cleanup the stale pending bits and check
* if there's anything left.
*/
if (scan_type == scan_eoi)
return hirq;
/*
* If we found an interrupt, adjust what the guest CPPR should
* be as if we had just fetched that interrupt from HW.
*
* Note: This can only make xc->cppr smaller as the previous
* loop will only exit with hirq != 0 if prio is lower than
* the current xc->cppr. Thus we don't need to re-check xc->mfrr
* for pending IPIs.
*/
if (hirq)
xc->cppr = prio;
/*
* If it was an IPI the HW CPPR might have been lowered too much
* as the HW interrupt we use for IPIs is routed to priority 0.
*
* We re-sync it here.
*/
if (xc->cppr != xc->hw_cppr) {
xc->hw_cppr = xc->cppr;
__raw_writeb(xc->cppr, xive_tima + TM_QW1_OS + TM_CPPR);
}
return hirq;
}
static unsigned long xive_vm_h_xirr(struct kvm_vcpu *vcpu)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
u8 old_cppr;
u32 hirq;
pr_devel("H_XIRR\n");
xc->stat_vm_h_xirr++;
/* First collect pending bits from HW */
xive_vm_ack_pending(xc);
pr_devel(" new pending=0x%02x hw_cppr=%d cppr=%d\n",
xc->pending, xc->hw_cppr, xc->cppr);
/* Grab previous CPPR and reverse map it */
old_cppr = xive_prio_to_guest(xc->cppr);
/* Scan for actual interrupts */
hirq = xive_vm_scan_interrupts(xc, xc->pending, scan_fetch);
pr_devel(" got hirq=0x%x hw_cppr=%d cppr=%d\n",
hirq, xc->hw_cppr, xc->cppr);
/* That should never hit */
if (hirq & 0xff000000)
pr_warn("XIVE: Weird guest interrupt number 0x%08x\n", hirq);
/*
* XXX We could check if the interrupt is masked here and
* filter it. If we chose to do so, we would need to do:
*
* if (masked) {
* lock();
* if (masked) {
* old_Q = true;
* hirq = 0;
* }
* unlock();
* }
*/
/* Return interrupt and old CPPR in GPR4 */
vcpu->arch.regs.gpr[4] = hirq | (old_cppr << 24);
return H_SUCCESS;
}
static unsigned long xive_vm_h_ipoll(struct kvm_vcpu *vcpu, unsigned long server)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
u8 pending = xc->pending;
u32 hirq;
pr_devel("H_IPOLL(server=%ld)\n", server);
xc->stat_vm_h_ipoll++;
/* Grab the target VCPU if not the current one */
if (xc->server_num != server) {
vcpu = kvmppc_xive_find_server(vcpu->kvm, server);
if (!vcpu)
return H_PARAMETER;
xc = vcpu->arch.xive_vcpu;
/* Scan all priorities */
pending = 0xff;
} else {
/* Grab pending interrupt if any */
__be64 qw1 = __raw_readq(xive_tima + TM_QW1_OS);
u8 pipr = be64_to_cpu(qw1) & 0xff;
if (pipr < 8)
pending |= 1 << pipr;
}
hirq = xive_vm_scan_interrupts(xc, pending, scan_poll);
/* Return interrupt and old CPPR in GPR4 */
vcpu->arch.regs.gpr[4] = hirq | (xc->cppr << 24);
return H_SUCCESS;
}
static void xive_vm_push_pending_to_hw(struct kvmppc_xive_vcpu *xc)
{
u8 pending, prio;
pending = xc->pending;
if (xc->mfrr != 0xff) {
if (xc->mfrr < 8)
pending |= 1 << xc->mfrr;
else
pending |= 0x80;
}
if (!pending)
return;
prio = ffs(pending) - 1;
__raw_writeb(prio, xive_tima + TM_SPC_SET_OS_PENDING);
}
static void xive_vm_scan_for_rerouted_irqs(struct kvmppc_xive *xive,
struct kvmppc_xive_vcpu *xc)
{
unsigned int prio;
/* For each priority that is now masked */
for (prio = xc->cppr; prio < KVMPPC_XIVE_Q_COUNT; prio++) {
struct xive_q *q = &xc->queues[prio];
struct kvmppc_xive_irq_state *state;
struct kvmppc_xive_src_block *sb;
u32 idx, toggle, entry, irq, hw_num;
struct xive_irq_data *xd;
__be32 *qpage;
u16 src;
idx = q->idx;
toggle = q->toggle;
qpage = READ_ONCE(q->qpage);
if (!qpage)
continue;
/* For each interrupt in the queue */
for (;;) {
entry = be32_to_cpup(qpage + idx);
/* No more ? */
if ((entry >> 31) == toggle)
break;
irq = entry & 0x7fffffff;
/* Skip dummies and IPIs */
if (irq == XICS_DUMMY || irq == XICS_IPI)
goto next;
sb = kvmppc_xive_find_source(xive, irq, &src);
if (!sb)
goto next;
state = &sb->irq_state[src];
/* Has it been rerouted ? */
if (xc->server_num == state->act_server)
goto next;
/*
* Allright, it *has* been re-routed, kill it from
* the queue.
*/
qpage[idx] = cpu_to_be32((entry & 0x80000000) | XICS_DUMMY);
/* Find the HW interrupt */
kvmppc_xive_select_irq(state, &hw_num, &xd);
/* If it's not an LSI, set PQ to 11 the EOI will force a resend */
if (!(xd->flags & XIVE_IRQ_FLAG_LSI))
xive_vm_esb_load(xd, XIVE_ESB_SET_PQ_11);
/* EOI the source */
xive_vm_source_eoi(hw_num, xd);
next:
idx = (idx + 1) & q->msk;
if (idx == 0)
toggle ^= 1;
}
}
}
static int xive_vm_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
struct kvmppc_xive *xive = vcpu->kvm->arch.xive;
u8 old_cppr;
pr_devel("H_CPPR(cppr=%ld)\n", cppr);
xc->stat_vm_h_cppr++;
/* Map CPPR */
cppr = xive_prio_from_guest(cppr);
/* Remember old and update SW state */
old_cppr = xc->cppr;
xc->cppr = cppr;
/*
* Order the above update of xc->cppr with the subsequent
* read of xc->mfrr inside push_pending_to_hw()
*/
smp_mb();
if (cppr > old_cppr) {
/*
* We are masking less, we need to look for pending things
* to deliver and set VP pending bits accordingly to trigger
* a new interrupt otherwise we might miss MFRR changes for
* which we have optimized out sending an IPI signal.
*/
xive_vm_push_pending_to_hw(xc);
} else {
/*
* We are masking more, we need to check the queue for any
* interrupt that has been routed to another CPU, take
* it out (replace it with the dummy) and retrigger it.
*
* This is necessary since those interrupts may otherwise
* never be processed, at least not until this CPU restores
* its CPPR.
*
* This is in theory racy vs. HW adding new interrupts to
* the queue. In practice this works because the interesting
* cases are when the guest has done a set_xive() to move the
* interrupt away, which flushes the xive, followed by the
* target CPU doing a H_CPPR. So any new interrupt coming into
* the queue must still be routed to us and isn't a source
* of concern.
*/
xive_vm_scan_for_rerouted_irqs(xive, xc);
}
/* Apply new CPPR */
xc->hw_cppr = cppr;
__raw_writeb(cppr, xive_tima + TM_QW1_OS + TM_CPPR);
return H_SUCCESS;
}
static int xive_vm_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
{
struct kvmppc_xive *xive = vcpu->kvm->arch.xive;
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
struct xive_irq_data *xd;
u8 new_cppr = xirr >> 24;
u32 irq = xirr & 0x00ffffff, hw_num;
u16 src;
int rc = 0;
pr_devel("H_EOI(xirr=%08lx)\n", xirr);
xc->stat_vm_h_eoi++;
xc->cppr = xive_prio_from_guest(new_cppr);
/*
* IPIs are synthetized from MFRR and thus don't need
* any special EOI handling. The underlying interrupt
* used to signal MFRR changes is EOId when fetched from
* the queue.
*/
if (irq == XICS_IPI || irq == 0) {
/*
* This barrier orders the setting of xc->cppr vs.
* subsequent test of xc->mfrr done inside
* scan_interrupts and push_pending_to_hw
*/
smp_mb();
goto bail;
}
/* Find interrupt source */
sb = kvmppc_xive_find_source(xive, irq, &src);
if (!sb) {
pr_devel(" source not found !\n");
rc = H_PARAMETER;
/* Same as above */
smp_mb();
goto bail;
}
state = &sb->irq_state[src];
kvmppc_xive_select_irq(state, &hw_num, &xd);
state->in_eoi = true;
/*
* This barrier orders both setting of in_eoi above vs,
* subsequent test of guest_priority, and the setting
* of xc->cppr vs. subsequent test of xc->mfrr done inside
* scan_interrupts and push_pending_to_hw
*/
smp_mb();
again:
if (state->guest_priority == MASKED) {
arch_spin_lock(&sb->lock);
if (state->guest_priority != MASKED) {
arch_spin_unlock(&sb->lock);
goto again;
}
pr_devel(" EOI on saved P...\n");
/* Clear old_p, that will cause unmask to perform an EOI */
state->old_p = false;
arch_spin_unlock(&sb->lock);
} else {
pr_devel(" EOI on source...\n");
/* Perform EOI on the source */
xive_vm_source_eoi(hw_num, xd);
/* If it's an emulated LSI, check level and resend */
if (state->lsi && state->asserted)
__raw_writeq(0, __x_trig_page(xd));
}
/*
* This barrier orders the above guest_priority check
* and spin_lock/unlock with clearing in_eoi below.
*
* It also has to be a full mb() as it must ensure
* the MMIOs done in source_eoi() are completed before
* state->in_eoi is visible.
*/
mb();
state->in_eoi = false;
bail:
/* Re-evaluate pending IRQs and update HW */
xive_vm_scan_interrupts(xc, xc->pending, scan_eoi);
xive_vm_push_pending_to_hw(xc);
pr_devel(" after scan pending=%02x\n", xc->pending);
/* Apply new CPPR */
xc->hw_cppr = xc->cppr;
__raw_writeb(xc->cppr, xive_tima + TM_QW1_OS + TM_CPPR);
return rc;
}
static int xive_vm_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
unsigned long mfrr)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
pr_devel("H_IPI(server=%08lx,mfrr=%ld)\n", server, mfrr);
xc->stat_vm_h_ipi++;
/* Find target */
vcpu = kvmppc_xive_find_server(vcpu->kvm, server);
if (!vcpu)
return H_PARAMETER;
xc = vcpu->arch.xive_vcpu;
/* Locklessly write over MFRR */
xc->mfrr = mfrr;
/*
* The load of xc->cppr below and the subsequent MMIO store
* to the IPI must happen after the above mfrr update is
* globally visible so that:
*
* - Synchronize with another CPU doing an H_EOI or a H_CPPR
* updating xc->cppr then reading xc->mfrr.
*
* - The target of the IPI sees the xc->mfrr update
*/
mb();
/* Shoot the IPI if most favored than target cppr */
if (mfrr < xc->cppr)
__raw_writeq(0, __x_trig_page(&xc->vp_ipi_data));
return H_SUCCESS;
}
/*
* We leave a gap of a couple of interrupts in the queue to
* account for the IPI and additional safety guard.
*/
#define XIVE_Q_GAP 2
static bool kvmppc_xive_vcpu_has_save_restore(struct kvm_vcpu *vcpu)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
/* Check enablement at VP level */
return xc->vp_cam & TM_QW1W2_HO;
}
bool kvmppc_xive_check_save_restore(struct kvm_vcpu *vcpu)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
struct kvmppc_xive *xive = xc->xive;
if (xive->flags & KVMPPC_XIVE_FLAG_SAVE_RESTORE)
return kvmppc_xive_vcpu_has_save_restore(vcpu);
return true;
}
/*
* Push a vcpu's context to the XIVE on guest entry.
* This assumes we are in virtual mode (MMU on)
*/
void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu)
{
void __iomem *tima = local_paca->kvm_hstate.xive_tima_virt;
u64 pq;
/*
* Nothing to do if the platform doesn't have a XIVE
* or this vCPU doesn't have its own XIVE context
* (e.g. because it's not using an in-kernel interrupt controller).
*/
if (!tima || !vcpu->arch.xive_cam_word)
return;
eieio();
if (!kvmppc_xive_vcpu_has_save_restore(vcpu))
__raw_writeq(vcpu->arch.xive_saved_state.w01, tima + TM_QW1_OS);
__raw_writel(vcpu->arch.xive_cam_word, tima + TM_QW1_OS + TM_WORD2);
vcpu->arch.xive_pushed = 1;
eieio();
/*
* We clear the irq_pending flag. There is a small chance of a
* race vs. the escalation interrupt happening on another
* processor setting it again, but the only consequence is to
* cause a spurious wakeup on the next H_CEDE, which is not an
* issue.
*/
vcpu->arch.irq_pending = 0;
/*
* In single escalation mode, if the escalation interrupt is
* on, we mask it.
*/
if (vcpu->arch.xive_esc_on) {
pq = __raw_readq((void __iomem *)(vcpu->arch.xive_esc_vaddr +
XIVE_ESB_SET_PQ_01));
mb();
/*
* We have a possible subtle race here: The escalation
* interrupt might have fired and be on its way to the
* host queue while we mask it, and if we unmask it
* early enough (re-cede right away), there is a
* theoretical possibility that it fires again, thus
* landing in the target queue more than once which is
* a big no-no.
*
* Fortunately, solving this is rather easy. If the
* above load setting PQ to 01 returns a previous
* value where P is set, then we know the escalation
* interrupt is somewhere on its way to the host. In
* that case we simply don't clear the xive_esc_on
* flag below. It will be eventually cleared by the
* handler for the escalation interrupt.
*
* Then, when doing a cede, we check that flag again
* before re-enabling the escalation interrupt, and if
* set, we abort the cede.
*/
if (!(pq & XIVE_ESB_VAL_P))
/* Now P is 0, we can clear the flag */
vcpu->arch.xive_esc_on = 0;
}
}
EXPORT_SYMBOL_GPL(kvmppc_xive_push_vcpu);
/*
* Pull a vcpu's context from the XIVE on guest exit.
* This assumes we are in virtual mode (MMU on)
*/
void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu)
{
void __iomem *tima = local_paca->kvm_hstate.xive_tima_virt;
if (!vcpu->arch.xive_pushed)
return;
/*
* Should not have been pushed if there is no tima
*/
if (WARN_ON(!tima))
return;
eieio();
/* First load to pull the context, we ignore the value */
__raw_readl(tima + TM_SPC_PULL_OS_CTX);
/* Second load to recover the context state (Words 0 and 1) */
if (!kvmppc_xive_vcpu_has_save_restore(vcpu))
vcpu->arch.xive_saved_state.w01 = __raw_readq(tima + TM_QW1_OS);
/* Fixup some of the state for the next load */
vcpu->arch.xive_saved_state.lsmfb = 0;
vcpu->arch.xive_saved_state.ack = 0xff;
vcpu->arch.xive_pushed = 0;
eieio();
}
EXPORT_SYMBOL_GPL(kvmppc_xive_pull_vcpu);
bool kvmppc_xive_rearm_escalation(struct kvm_vcpu *vcpu)
{
void __iomem *esc_vaddr = (void __iomem *)vcpu->arch.xive_esc_vaddr;
bool ret = true;
if (!esc_vaddr)
return ret;
/* we are using XIVE with single escalation */
if (vcpu->arch.xive_esc_on) {
/*
* If we still have a pending escalation, abort the cede,
* and we must set PQ to 10 rather than 00 so that we don't
* potentially end up with two entries for the escalation
* interrupt in the XIVE interrupt queue. In that case
* we also don't want to set xive_esc_on to 1 here in
* case we race with xive_esc_irq().
*/
ret = false;
/*
* The escalation interrupts are special as we don't EOI them.
* There is no need to use the load-after-store ordering offset
* to set PQ to 10 as we won't use StoreEOI.
*/
__raw_readq(esc_vaddr + XIVE_ESB_SET_PQ_10);
} else {
vcpu->arch.xive_esc_on = true;
mb();
__raw_readq(esc_vaddr + XIVE_ESB_SET_PQ_00);
}
mb();
return ret;
}
EXPORT_SYMBOL_GPL(kvmppc_xive_rearm_escalation);
/*
* This is a simple trigger for a generic XIVE IRQ. This must
* only be called for interrupts that support a trigger page
*/
static bool xive_irq_trigger(struct xive_irq_data *xd)
{
/* This should be only for MSIs */
if (WARN_ON(xd->flags & XIVE_IRQ_FLAG_LSI))
return false;
/* Those interrupts should always have a trigger page */
if (WARN_ON(!xd->trig_mmio))
return false;
out_be64(xd->trig_mmio, 0);
return true;
}
static irqreturn_t xive_esc_irq(int irq, void *data)
{
struct kvm_vcpu *vcpu = data;
vcpu->arch.irq_pending = 1;
smp_mb();
if (vcpu->arch.ceded || vcpu->arch.nested)
kvmppc_fast_vcpu_kick(vcpu);
/* Since we have the no-EOI flag, the interrupt is effectively
* disabled now. Clearing xive_esc_on means we won't bother
* doing so on the next entry.
*
* This also allows the entry code to know that if a PQ combination
* of 10 is observed while xive_esc_on is true, it means the queue
* contains an unprocessed escalation interrupt. We don't make use of
* that knowledge today but might (see comment in book3s_hv_rmhandler.S)
*/
vcpu->arch.xive_esc_on = false;
/* This orders xive_esc_on = false vs. subsequent stale_p = true */
smp_wmb(); /* goes with smp_mb() in cleanup_single_escalation */
return IRQ_HANDLED;
}
int kvmppc_xive_attach_escalation(struct kvm_vcpu *vcpu, u8 prio,
bool single_escalation)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
struct xive_q *q = &xc->queues[prio];
char *name = NULL;
int rc;
/* Already there ? */
if (xc->esc_virq[prio])
return 0;
/* Hook up the escalation interrupt */
xc->esc_virq[prio] = irq_create_mapping(NULL, q->esc_irq);
if (!xc->esc_virq[prio]) {
pr_err("Failed to map escalation interrupt for queue %d of VCPU %d\n",
prio, xc->server_num);
return -EIO;
}
if (single_escalation)
name = kasprintf(GFP_KERNEL, "kvm-%d-%d",
vcpu->kvm->arch.lpid, xc->server_num);
else
name = kasprintf(GFP_KERNEL, "kvm-%d-%d-%d",
vcpu->kvm->arch.lpid, xc->server_num, prio);
if (!name) {
pr_err("Failed to allocate escalation irq name for queue %d of VCPU %d\n",
prio, xc->server_num);
rc = -ENOMEM;
goto error;
}
pr_devel("Escalation %s irq %d (prio %d)\n", name, xc->esc_virq[prio], prio);
rc = request_irq(xc->esc_virq[prio], xive_esc_irq,
IRQF_NO_THREAD, name, vcpu);
if (rc) {
pr_err("Failed to request escalation interrupt for queue %d of VCPU %d\n",
prio, xc->server_num);
goto error;
}
xc->esc_virq_names[prio] = name;
/* In single escalation mode, we grab the ESB MMIO of the
* interrupt and mask it. Also populate the VCPU v/raddr
* of the ESB page for use by asm entry/exit code. Finally
* set the XIVE_IRQ_FLAG_NO_EOI flag which will prevent the
* core code from performing an EOI on the escalation
* interrupt, thus leaving it effectively masked after
* it fires once.
*/
if (single_escalation) {
struct irq_data *d = irq_get_irq_data(xc->esc_virq[prio]);
struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
xive_vm_esb_load(xd, XIVE_ESB_SET_PQ_01);
vcpu->arch.xive_esc_raddr = xd->eoi_page;
vcpu->arch.xive_esc_vaddr = (__force u64)xd->eoi_mmio;
xd->flags |= XIVE_IRQ_FLAG_NO_EOI;
}
return 0;
error:
irq_dispose_mapping(xc->esc_virq[prio]);
xc->esc_virq[prio] = 0;
kfree(name);
return rc;
}
static int xive_provision_queue(struct kvm_vcpu *vcpu, u8 prio)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
struct kvmppc_xive *xive = xc->xive;
struct xive_q *q = &xc->queues[prio];
void *qpage;
int rc;
if (WARN_ON(q->qpage))
return 0;
/* Allocate the queue and retrieve infos on current node for now */
qpage = (__be32 *)__get_free_pages(GFP_KERNEL, xive->q_page_order);
if (!qpage) {
pr_err("Failed to allocate queue %d for VCPU %d\n",
prio, xc->server_num);
return -ENOMEM;
}
memset(qpage, 0, 1 << xive->q_order);
/*
* Reconfigure the queue. This will set q->qpage only once the
* queue is fully configured. This is a requirement for prio 0
* as we will stop doing EOIs for every IPI as soon as we observe
* qpage being non-NULL, and instead will only EOI when we receive
* corresponding queue 0 entries
*/
rc = xive_native_configure_queue(xc->vp_id, q, prio, qpage,
xive->q_order, true);
if (rc)
pr_err("Failed to configure queue %d for VCPU %d\n",
prio, xc->server_num);
return rc;
}
/* Called with xive->lock held */
static int xive_check_provisioning(struct kvm *kvm, u8 prio)
{
struct kvmppc_xive *xive = kvm->arch.xive;
struct kvm_vcpu *vcpu;
unsigned long i;
int rc;
lockdep_assert_held(&xive->lock);
/* Already provisioned ? */
if (xive->qmap & (1 << prio))
return 0;
pr_devel("Provisioning prio... %d\n", prio);
/* Provision each VCPU and enable escalations if needed */
kvm_for_each_vcpu(i, vcpu, kvm) {
if (!vcpu->arch.xive_vcpu)
continue;
rc = xive_provision_queue(vcpu, prio);
if (rc == 0 && !kvmppc_xive_has_single_escalation(xive))
kvmppc_xive_attach_escalation(vcpu, prio,
kvmppc_xive_has_single_escalation(xive));
if (rc)
return rc;
}
/* Order previous stores and mark it as provisioned */
mb();
xive->qmap |= (1 << prio);
return 0;
}
static void xive_inc_q_pending(struct kvm *kvm, u32 server, u8 prio)
{
struct kvm_vcpu *vcpu;
struct kvmppc_xive_vcpu *xc;
struct xive_q *q;
/* Locate target server */
vcpu = kvmppc_xive_find_server(kvm, server);
if (!vcpu) {
pr_warn("%s: Can't find server %d\n", __func__, server);
return;
}
xc = vcpu->arch.xive_vcpu;
if (WARN_ON(!xc))
return;
q = &xc->queues[prio];
atomic_inc(&q->pending_count);
}
static int xive_try_pick_queue(struct kvm_vcpu *vcpu, u8 prio)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
struct xive_q *q;
u32 max;
if (WARN_ON(!xc))
return -ENXIO;
if (!xc->valid)
return -ENXIO;
q = &xc->queues[prio];
if (WARN_ON(!q->qpage))
return -ENXIO;
/* Calculate max number of interrupts in that queue. */
max = (q->msk + 1) - XIVE_Q_GAP;
return atomic_add_unless(&q->count, 1, max) ? 0 : -EBUSY;
}
int kvmppc_xive_select_target(struct kvm *kvm, u32 *server, u8 prio)
{
struct kvm_vcpu *vcpu;
unsigned long i;
int rc;
/* Locate target server */
vcpu = kvmppc_xive_find_server(kvm, *server);
if (!vcpu) {
pr_devel("Can't find server %d\n", *server);
return -EINVAL;
}
pr_devel("Finding irq target on 0x%x/%d...\n", *server, prio);
/* Try pick it */
rc = xive_try_pick_queue(vcpu, prio);
if (rc == 0)
return rc;
pr_devel(" .. failed, looking up candidate...\n");
/* Failed, pick another VCPU */
kvm_for_each_vcpu(i, vcpu, kvm) {
if (!vcpu->arch.xive_vcpu)
continue;
rc = xive_try_pick_queue(vcpu, prio);
if (rc == 0) {
*server = vcpu->arch.xive_vcpu->server_num;
pr_devel(" found on 0x%x/%d\n", *server, prio);
return rc;
}
}
pr_devel(" no available target !\n");
/* No available target ! */
return -EBUSY;
}
static u8 xive_lock_and_mask(struct kvmppc_xive *xive,
struct kvmppc_xive_src_block *sb,
struct kvmppc_xive_irq_state *state)
{
struct xive_irq_data *xd;
u32 hw_num;
u8 old_prio;
u64 val;
/*
* Take the lock, set masked, try again if racing
* with H_EOI
*/
for (;;) {
arch_spin_lock(&sb->lock);
old_prio = state->guest_priority;
state->guest_priority = MASKED;
mb();
if (!state->in_eoi)
break;
state->guest_priority = old_prio;
arch_spin_unlock(&sb->lock);
}
/* No change ? Bail */
if (old_prio == MASKED)
return old_prio;
/* Get the right irq */
kvmppc_xive_select_irq(state, &hw_num, &xd);
/* Set PQ to 10, return old P and old Q and remember them */
val = xive_vm_esb_load(xd, XIVE_ESB_SET_PQ_10);
state->old_p = !!(val & 2);
state->old_q = !!(val & 1);
/*
* Synchronize hardware to sensure the queues are updated when
* masking
*/
xive_native_sync_source(hw_num);
return old_prio;
}
static void xive_lock_for_unmask(struct kvmppc_xive_src_block *sb,
struct kvmppc_xive_irq_state *state)
{
/*
* Take the lock try again if racing with H_EOI
*/
for (;;) {
arch_spin_lock(&sb->lock);
if (!state->in_eoi)
break;
arch_spin_unlock(&sb->lock);
}
}
static void xive_finish_unmask(struct kvmppc_xive *xive,
struct kvmppc_xive_src_block *sb,
struct kvmppc_xive_irq_state *state,
u8 prio)
{
struct xive_irq_data *xd;
u32 hw_num;
/* If we aren't changing a thing, move on */
if (state->guest_priority != MASKED)
goto bail;
/* Get the right irq */
kvmppc_xive_select_irq(state, &hw_num, &xd);
/* Old Q set, set PQ to 11 */
if (state->old_q)
xive_vm_esb_load(xd, XIVE_ESB_SET_PQ_11);
/*
* If not old P, then perform an "effective" EOI,
* on the source. This will handle the cases where
* FW EOI is needed.
*/
if (!state->old_p)
xive_vm_source_eoi(hw_num, xd);
/* Synchronize ordering and mark unmasked */
mb();
bail:
state->guest_priority = prio;
}
/*
* Target an interrupt to a given server/prio, this will fallback
* to another server if necessary and perform the HW targetting
* updates as needed
*
* NOTE: Must be called with the state lock held
*/
static int xive_target_interrupt(struct kvm *kvm,
struct kvmppc_xive_irq_state *state,
u32 server, u8 prio)
{
struct kvmppc_xive *xive = kvm->arch.xive;
u32 hw_num;
int rc;
/*
* This will return a tentative server and actual
* priority. The count for that new target will have
* already been incremented.
*/
rc = kvmppc_xive_select_target(kvm, &server, prio);
/*
* We failed to find a target ? Not much we can do
* at least until we support the GIQ.
*/
if (rc)
return rc;
/*
* Increment the old queue pending count if there
* was one so that the old queue count gets adjusted later
* when observed to be empty.
*/
if (state->act_priority != MASKED)
xive_inc_q_pending(kvm,
state->act_server,
state->act_priority);
/*
* Update state and HW
*/
state->act_priority = prio;
state->act_server = server;
/* Get the right irq */
kvmppc_xive_select_irq(state, &hw_num, NULL);
return xive_native_configure_irq(hw_num,
kvmppc_xive_vp(xive, server),
prio, state->number);
}
/*
* Targetting rules: In order to avoid losing track of
* pending interrupts across mask and unmask, which would
* allow queue overflows, we implement the following rules:
*
* - Unless it was never enabled (or we run out of capacity)
* an interrupt is always targetted at a valid server/queue
* pair even when "masked" by the guest. This pair tends to
* be the last one used but it can be changed under some
* circumstances. That allows us to separate targetting
* from masking, we only handle accounting during (re)targetting,
* this also allows us to let an interrupt drain into its target
* queue after masking, avoiding complex schemes to remove
* interrupts out of remote processor queues.
*
* - When masking, we set PQ to 10 and save the previous value
* of P and Q.
*
* - When unmasking, if saved Q was set, we set PQ to 11
* otherwise we leave PQ to the HW state which will be either
* 10 if nothing happened or 11 if the interrupt fired while
* masked. Effectively we are OR'ing the previous Q into the
* HW Q.
*
* Then if saved P is clear, we do an effective EOI (Q->P->Trigger)
* which will unmask the interrupt and shoot a new one if Q was
* set.
*
* Otherwise (saved P is set) we leave PQ unchanged (so 10 or 11,
* effectively meaning an H_EOI from the guest is still expected
* for that interrupt).
*
* - If H_EOI occurs while masked, we clear the saved P.
*
* - When changing target, we account on the new target and
* increment a separate "pending" counter on the old one.
* This pending counter will be used to decrement the old
* target's count when its queue has been observed empty.
*/
int kvmppc_xive_set_xive(struct kvm *kvm, u32 irq, u32 server,
u32 priority)
{
struct kvmppc_xive *xive = kvm->arch.xive;
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
u8 new_act_prio;
int rc = 0;
u16 idx;
if (!xive)
return -ENODEV;
pr_devel("set_xive ! irq 0x%x server 0x%x prio %d\n",
irq, server, priority);
/* First, check provisioning of queues */
if (priority != MASKED) {
mutex_lock(&xive->lock);
rc = xive_check_provisioning(xive->kvm,
xive_prio_from_guest(priority));
mutex_unlock(&xive->lock);
}
if (rc) {
pr_devel(" provisioning failure %d !\n", rc);
return rc;
}
sb = kvmppc_xive_find_source(xive, irq, &idx);
if (!sb)
return -EINVAL;
state = &sb->irq_state[idx];
/*
* We first handle masking/unmasking since the locking
* might need to be retried due to EOIs, we'll handle
* targetting changes later. These functions will return
* with the SB lock held.
*
* xive_lock_and_mask() will also set state->guest_priority
* but won't otherwise change other fields of the state.
*
* xive_lock_for_unmask will not actually unmask, this will
* be done later by xive_finish_unmask() once the targetting
* has been done, so we don't try to unmask an interrupt
* that hasn't yet been targetted.
*/
if (priority == MASKED)
xive_lock_and_mask(xive, sb, state);
else
xive_lock_for_unmask(sb, state);
/*
* Then we handle targetting.
*
* First calculate a new "actual priority"
*/
new_act_prio = state->act_priority;
if (priority != MASKED)
new_act_prio = xive_prio_from_guest(priority);
pr_devel(" new_act_prio=%x act_server=%x act_prio=%x\n",
new_act_prio, state->act_server, state->act_priority);
/*
* Then check if we actually need to change anything,
*
* The condition for re-targetting the interrupt is that
* we have a valid new priority (new_act_prio is not 0xff)
* and either the server or the priority changed.
*
* Note: If act_priority was ff and the new priority is
* also ff, we don't do anything and leave the interrupt
* untargetted. An attempt of doing an int_on on an
* untargetted interrupt will fail. If that is a problem
* we could initialize interrupts with valid default
*/
if (new_act_prio != MASKED &&
(state->act_server != server ||
state->act_priority != new_act_prio))
rc = xive_target_interrupt(kvm, state, server, new_act_prio);
/*
* Perform the final unmasking of the interrupt source
* if necessary
*/
if (priority != MASKED)
xive_finish_unmask(xive, sb, state, priority);
/*
* Finally Update saved_priority to match. Only int_on/off
* set this field to a different value.
*/
state->saved_priority = priority;
arch_spin_unlock(&sb->lock);
return rc;
}
int kvmppc_xive_get_xive(struct kvm *kvm, u32 irq, u32 *server,
u32 *priority)
{
struct kvmppc_xive *xive = kvm->arch.xive;
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
u16 idx;
if (!xive)
return -ENODEV;
sb = kvmppc_xive_find_source(xive, irq, &idx);
if (!sb)
return -EINVAL;
state = &sb->irq_state[idx];
arch_spin_lock(&sb->lock);
*server = state->act_server;
*priority = state->guest_priority;
arch_spin_unlock(&sb->lock);
return 0;
}
int kvmppc_xive_int_on(struct kvm *kvm, u32 irq)
{
struct kvmppc_xive *xive = kvm->arch.xive;
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
u16 idx;
if (!xive)
return -ENODEV;
sb = kvmppc_xive_find_source(xive, irq, &idx);
if (!sb)
return -EINVAL;
state = &sb->irq_state[idx];
pr_devel("int_on(irq=0x%x)\n", irq);
/*
* Check if interrupt was not targetted
*/
if (state->act_priority == MASKED) {
pr_devel("int_on on untargetted interrupt\n");
return -EINVAL;
}
/* If saved_priority is 0xff, do nothing */
if (state->saved_priority == MASKED)
return 0;
/*
* Lock and unmask it.
*/
xive_lock_for_unmask(sb, state);
xive_finish_unmask(xive, sb, state, state->saved_priority);
arch_spin_unlock(&sb->lock);
return 0;
}
int kvmppc_xive_int_off(struct kvm *kvm, u32 irq)
{
struct kvmppc_xive *xive = kvm->arch.xive;
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
u16 idx;
if (!xive)
return -ENODEV;
sb = kvmppc_xive_find_source(xive, irq, &idx);
if (!sb)
return -EINVAL;
state = &sb->irq_state[idx];
pr_devel("int_off(irq=0x%x)\n", irq);
/*
* Lock and mask
*/
state->saved_priority = xive_lock_and_mask(xive, sb, state);
arch_spin_unlock(&sb->lock);
return 0;
}
static bool xive_restore_pending_irq(struct kvmppc_xive *xive, u32 irq)
{
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
u16 idx;
sb = kvmppc_xive_find_source(xive, irq, &idx);
if (!sb)
return false;
state = &sb->irq_state[idx];
if (!state->valid)
return false;
/*
* Trigger the IPI. This assumes we never restore a pass-through
* interrupt which should be safe enough
*/
xive_irq_trigger(&state->ipi_data);
return true;
}
u64 kvmppc_xive_get_icp(struct kvm_vcpu *vcpu)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
if (!xc)
return 0;
/* Return the per-cpu state for state saving/migration */
return (u64)xc->cppr << KVM_REG_PPC_ICP_CPPR_SHIFT |
(u64)xc->mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT |
(u64)0xff << KVM_REG_PPC_ICP_PPRI_SHIFT;
}
int kvmppc_xive_set_icp(struct kvm_vcpu *vcpu, u64 icpval)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
struct kvmppc_xive *xive = vcpu->kvm->arch.xive;
u8 cppr, mfrr;
u32 xisr;
if (!xc || !xive)
return -ENOENT;
/* Grab individual state fields. We don't use pending_pri */
cppr = icpval >> KVM_REG_PPC_ICP_CPPR_SHIFT;
xisr = (icpval >> KVM_REG_PPC_ICP_XISR_SHIFT) &
KVM_REG_PPC_ICP_XISR_MASK;
mfrr = icpval >> KVM_REG_PPC_ICP_MFRR_SHIFT;
pr_devel("set_icp vcpu %d cppr=0x%x mfrr=0x%x xisr=0x%x\n",
xc->server_num, cppr, mfrr, xisr);
/*
* We can't update the state of a "pushed" VCPU, but that
* shouldn't happen because the vcpu->mutex makes running a
* vcpu mutually exclusive with doing one_reg get/set on it.
*/
if (WARN_ON(vcpu->arch.xive_pushed))
return -EIO;
/* Update VCPU HW saved state */
vcpu->arch.xive_saved_state.cppr = cppr;
xc->hw_cppr = xc->cppr = cppr;
/*
* Update MFRR state. If it's not 0xff, we mark the VCPU as
* having a pending MFRR change, which will re-evaluate the
* target. The VCPU will thus potentially get a spurious
* interrupt but that's not a big deal.
*/
xc->mfrr = mfrr;
if (mfrr < cppr)
xive_irq_trigger(&xc->vp_ipi_data);
/*
* Now saved XIRR is "interesting". It means there's something in
* the legacy "1 element" queue... for an IPI we simply ignore it,
* as the MFRR restore will handle that. For anything else we need
* to force a resend of the source.
* However the source may not have been setup yet. If that's the
* case, we keep that info and increment a counter in the xive to
* tell subsequent xive_set_source() to go look.
*/
if (xisr > XICS_IPI && !xive_restore_pending_irq(xive, xisr)) {
xc->delayed_irq = xisr;
xive->delayed_irqs++;
pr_devel(" xisr restore delayed\n");
}
return 0;
}
int kvmppc_xive_set_mapped(struct kvm *kvm, unsigned long guest_irq,
unsigned long host_irq)
{
struct kvmppc_xive *xive = kvm->arch.xive;
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
struct irq_data *host_data =
irq_domain_get_irq_data(irq_get_default_host(), host_irq);
unsigned int hw_irq = (unsigned int)irqd_to_hwirq(host_data);
u16 idx;
u8 prio;
int rc;
if (!xive)
return -ENODEV;
pr_debug("%s: GIRQ 0x%lx host IRQ %ld XIVE HW IRQ 0x%x\n",
__func__, guest_irq, host_irq, hw_irq);
sb = kvmppc_xive_find_source(xive, guest_irq, &idx);
if (!sb)
return -EINVAL;
state = &sb->irq_state[idx];
/*
* Mark the passed-through interrupt as going to a VCPU,
* this will prevent further EOIs and similar operations
* from the XIVE code. It will also mask the interrupt
* to either PQ=10 or 11 state, the latter if the interrupt
* is pending. This will allow us to unmask or retrigger it
* after routing it to the guest with a simple EOI.
*
* The "state" argument is a "token", all it needs is to be
* non-NULL to switch to passed-through or NULL for the
* other way around. We may not yet have an actual VCPU
* target here and we don't really care.
*/
rc = irq_set_vcpu_affinity(host_irq, state);
if (rc) {
pr_err("Failed to set VCPU affinity for host IRQ %ld\n", host_irq);
return rc;
}
/*
* Mask and read state of IPI. We need to know if its P bit
* is set as that means it's potentially already using a
* queue entry in the target
*/
prio = xive_lock_and_mask(xive, sb, state);
pr_devel(" old IPI prio %02x P:%d Q:%d\n", prio,
state->old_p, state->old_q);
/* Turn the IPI hard off */
xive_vm_esb_load(&state->ipi_data, XIVE_ESB_SET_PQ_01);
/*
* Reset ESB guest mapping. Needed when ESB pages are exposed
* to the guest in XIVE native mode
*/
if (xive->ops && xive->ops->reset_mapped)
xive->ops->reset_mapped(kvm, guest_irq);
/* Grab info about irq */
state->pt_number = hw_irq;
state->pt_data = irq_data_get_irq_handler_data(host_data);
/*
* Configure the IRQ to match the existing configuration of
* the IPI if it was already targetted. Otherwise this will
* mask the interrupt in a lossy way (act_priority is 0xff)
* which is fine for a never started interrupt.
*/
xive_native_configure_irq(hw_irq,
kvmppc_xive_vp(xive, state->act_server),
state->act_priority, state->number);
/*
* We do an EOI to enable the interrupt (and retrigger if needed)
* if the guest has the interrupt unmasked and the P bit was *not*
* set in the IPI. If it was set, we know a slot may still be in
* use in the target queue thus we have to wait for a guest
* originated EOI
*/
if (prio != MASKED && !state->old_p)
xive_vm_source_eoi(hw_irq, state->pt_data);
/* Clear old_p/old_q as they are no longer relevant */
state->old_p = state->old_q = false;
/* Restore guest prio (unlocks EOI) */
mb();
state->guest_priority = prio;
arch_spin_unlock(&sb->lock);
return 0;
}
EXPORT_SYMBOL_GPL(kvmppc_xive_set_mapped);
int kvmppc_xive_clr_mapped(struct kvm *kvm, unsigned long guest_irq,
unsigned long host_irq)
{
struct kvmppc_xive *xive = kvm->arch.xive;
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
u16 idx;
u8 prio;
int rc;
if (!xive)
return -ENODEV;
pr_debug("%s: GIRQ 0x%lx host IRQ %ld\n", __func__, guest_irq, host_irq);
sb = kvmppc_xive_find_source(xive, guest_irq, &idx);
if (!sb)
return -EINVAL;
state = &sb->irq_state[idx];
/*
* Mask and read state of IRQ. We need to know if its P bit
* is set as that means it's potentially already using a
* queue entry in the target
*/
prio = xive_lock_and_mask(xive, sb, state);
pr_devel(" old IRQ prio %02x P:%d Q:%d\n", prio,
state->old_p, state->old_q);
/*
* If old_p is set, the interrupt is pending, we switch it to
* PQ=11. This will force a resend in the host so the interrupt
* isn't lost to whatever host driver may pick it up
*/
if (state->old_p)
xive_vm_esb_load(state->pt_data, XIVE_ESB_SET_PQ_11);
/* Release the passed-through interrupt to the host */
rc = irq_set_vcpu_affinity(host_irq, NULL);
if (rc) {
pr_err("Failed to clr VCPU affinity for host IRQ %ld\n", host_irq);
return rc;
}
/* Forget about the IRQ */
state->pt_number = 0;
state->pt_data = NULL;
/*
* Reset ESB guest mapping. Needed when ESB pages are exposed
* to the guest in XIVE native mode
*/
if (xive->ops && xive->ops->reset_mapped) {
xive->ops->reset_mapped(kvm, guest_irq);
}
/* Reconfigure the IPI */
xive_native_configure_irq(state->ipi_number,
kvmppc_xive_vp(xive, state->act_server),
state->act_priority, state->number);
/*
* If old_p is set (we have a queue entry potentially
* occupied) or the interrupt is masked, we set the IPI
* to PQ=10 state. Otherwise we just re-enable it (PQ=00).
*/
if (prio == MASKED || state->old_p)
xive_vm_esb_load(&state->ipi_data, XIVE_ESB_SET_PQ_10);
else
xive_vm_esb_load(&state->ipi_data, XIVE_ESB_SET_PQ_00);
/* Restore guest prio (unlocks EOI) */
mb();
state->guest_priority = prio;
arch_spin_unlock(&sb->lock);
return 0;
}
EXPORT_SYMBOL_GPL(kvmppc_xive_clr_mapped);
void kvmppc_xive_disable_vcpu_interrupts(struct kvm_vcpu *vcpu)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
struct kvm *kvm = vcpu->kvm;
struct kvmppc_xive *xive = kvm->arch.xive;
int i, j;
for (i = 0; i <= xive->max_sbid; i++) {
struct kvmppc_xive_src_block *sb = xive->src_blocks[i];
if (!sb)
continue;
for (j = 0; j < KVMPPC_XICS_IRQ_PER_ICS; j++) {
struct kvmppc_xive_irq_state *state = &sb->irq_state[j];
if (!state->valid)
continue;
if (state->act_priority == MASKED)
continue;
if (state->act_server != xc->server_num)
continue;
/* Clean it up */
arch_spin_lock(&sb->lock);
state->act_priority = MASKED;
xive_vm_esb_load(&state->ipi_data, XIVE_ESB_SET_PQ_01);
xive_native_configure_irq(state->ipi_number, 0, MASKED, 0);
if (state->pt_number) {
xive_vm_esb_load(state->pt_data, XIVE_ESB_SET_PQ_01);
xive_native_configure_irq(state->pt_number, 0, MASKED, 0);
}
arch_spin_unlock(&sb->lock);
}
}
/* Disable vcpu's escalation interrupt */
if (vcpu->arch.xive_esc_on) {
__raw_readq((void __iomem *)(vcpu->arch.xive_esc_vaddr +
XIVE_ESB_SET_PQ_01));
vcpu->arch.xive_esc_on = false;
}
/*
* Clear pointers to escalation interrupt ESB.
* This is safe because the vcpu->mutex is held, preventing
* any other CPU from concurrently executing a KVM_RUN ioctl.
*/
vcpu->arch.xive_esc_vaddr = 0;
vcpu->arch.xive_esc_raddr = 0;
}
/*
* In single escalation mode, the escalation interrupt is marked so
* that EOI doesn't re-enable it, but just sets the stale_p flag to
* indicate that the P bit has already been dealt with. However, the
* assembly code that enters the guest sets PQ to 00 without clearing
* stale_p (because it has no easy way to address it). Hence we have
* to adjust stale_p before shutting down the interrupt.
*/
void xive_cleanup_single_escalation(struct kvm_vcpu *vcpu, int irq)
{
struct irq_data *d = irq_get_irq_data(irq);
struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
/*
* This slightly odd sequence gives the right result
* (i.e. stale_p set if xive_esc_on is false) even if
* we race with xive_esc_irq() and xive_irq_eoi().
*/
xd->stale_p = false;
smp_mb(); /* paired with smb_wmb in xive_esc_irq */
if (!vcpu->arch.xive_esc_on)
xd->stale_p = true;
}
void kvmppc_xive_cleanup_vcpu(struct kvm_vcpu *vcpu)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
struct kvmppc_xive *xive = vcpu->kvm->arch.xive;
int i;
if (!kvmppc_xics_enabled(vcpu))
return;
if (!xc)
return;
pr_devel("cleanup_vcpu(cpu=%d)\n", xc->server_num);
/* Ensure no interrupt is still routed to that VP */
xc->valid = false;
kvmppc_xive_disable_vcpu_interrupts(vcpu);
/* Mask the VP IPI */
xive_vm_esb_load(&xc->vp_ipi_data, XIVE_ESB_SET_PQ_01);
/* Free escalations */
for (i = 0; i < KVMPPC_XIVE_Q_COUNT; i++) {
if (xc->esc_virq[i]) {
if (kvmppc_xive_has_single_escalation(xc->xive))
xive_cleanup_single_escalation(vcpu, xc->esc_virq[i]);
free_irq(xc->esc_virq[i], vcpu);
irq_dispose_mapping(xc->esc_virq[i]);
kfree(xc->esc_virq_names[i]);
}
}
/* Disable the VP */
xive_native_disable_vp(xc->vp_id);
/* Clear the cam word so guest entry won't try to push context */
vcpu->arch.xive_cam_word = 0;
/* Free the queues */
for (i = 0; i < KVMPPC_XIVE_Q_COUNT; i++) {
struct xive_q *q = &xc->queues[i];
xive_native_disable_queue(xc->vp_id, q, i);
if (q->qpage) {
free_pages((unsigned long)q->qpage,
xive->q_page_order);
q->qpage = NULL;
}
}
/* Free the IPI */
if (xc->vp_ipi) {
xive_cleanup_irq_data(&xc->vp_ipi_data);
xive_native_free_irq(xc->vp_ipi);
}
/* Free the VP */
kfree(xc);
/* Cleanup the vcpu */
vcpu->arch.irq_type = KVMPPC_IRQ_DEFAULT;
vcpu->arch.xive_vcpu = NULL;
}
static bool kvmppc_xive_vcpu_id_valid(struct kvmppc_xive *xive, u32 cpu)
{
/* We have a block of xive->nr_servers VPs. We just need to check
* packed vCPU ids are below that.
*/
return kvmppc_pack_vcpu_id(xive->kvm, cpu) < xive->nr_servers;
}
int kvmppc_xive_compute_vp_id(struct kvmppc_xive *xive, u32 cpu, u32 *vp)
{
u32 vp_id;
if (!kvmppc_xive_vcpu_id_valid(xive, cpu)) {
pr_devel("Out of bounds !\n");
return -EINVAL;
}
if (xive->vp_base == XIVE_INVALID_VP) {
xive->vp_base = xive_native_alloc_vp_block(xive->nr_servers);
pr_devel("VP_Base=%x nr_servers=%d\n", xive->vp_base, xive->nr_servers);
if (xive->vp_base == XIVE_INVALID_VP)
return -ENOSPC;
}
vp_id = kvmppc_xive_vp(xive, cpu);
if (kvmppc_xive_vp_in_use(xive->kvm, vp_id)) {
pr_devel("Duplicate !\n");
return -EEXIST;
}
*vp = vp_id;
return 0;
}
int kvmppc_xive_connect_vcpu(struct kvm_device *dev,
struct kvm_vcpu *vcpu, u32 cpu)
{
struct kvmppc_xive *xive = dev->private;
struct kvmppc_xive_vcpu *xc;
int i, r = -EBUSY;
u32 vp_id;
pr_devel("connect_vcpu(cpu=%d)\n", cpu);
if (dev->ops != &kvm_xive_ops) {
pr_devel("Wrong ops !\n");
return -EPERM;
}
if (xive->kvm != vcpu->kvm)
return -EPERM;
if (vcpu->arch.irq_type != KVMPPC_IRQ_DEFAULT)
return -EBUSY;
/* We need to synchronize with queue provisioning */
mutex_lock(&xive->lock);
r = kvmppc_xive_compute_vp_id(xive, cpu, &vp_id);
if (r)
goto bail;
xc = kzalloc(sizeof(*xc), GFP_KERNEL);
if (!xc) {
r = -ENOMEM;
goto bail;
}
vcpu->arch.xive_vcpu = xc;
xc->xive = xive;
xc->vcpu = vcpu;
xc->server_num = cpu;
xc->vp_id = vp_id;
xc->mfrr = 0xff;
xc->valid = true;
r = xive_native_get_vp_info(xc->vp_id, &xc->vp_cam, &xc->vp_chip_id);
if (r)
goto bail;
if (!kvmppc_xive_check_save_restore(vcpu)) {
pr_err("inconsistent save-restore setup for VCPU %d\n", cpu);
r = -EIO;
goto bail;
}
/* Configure VCPU fields for use by assembly push/pull */
vcpu->arch.xive_saved_state.w01 = cpu_to_be64(0xff000000);
vcpu->arch.xive_cam_word = cpu_to_be32(xc->vp_cam | TM_QW1W2_VO);
/* Allocate IPI */
xc->vp_ipi = xive_native_alloc_irq();
if (!xc->vp_ipi) {
pr_err("Failed to allocate xive irq for VCPU IPI\n");
r = -EIO;
goto bail;
}
pr_devel(" IPI=0x%x\n", xc->vp_ipi);
r = xive_native_populate_irq_data(xc->vp_ipi, &xc->vp_ipi_data);
if (r)
goto bail;
/*
* Enable the VP first as the single escalation mode will
* affect escalation interrupts numbering
*/
r = xive_native_enable_vp(xc->vp_id, kvmppc_xive_has_single_escalation(xive));
if (r) {
pr_err("Failed to enable VP in OPAL, err %d\n", r);
goto bail;
}
/*
* Initialize queues. Initially we set them all for no queueing
* and we enable escalation for queue 0 only which we'll use for
* our mfrr change notifications. If the VCPU is hot-plugged, we
* do handle provisioning however based on the existing "map"
* of enabled queues.
*/
for (i = 0; i < KVMPPC_XIVE_Q_COUNT; i++) {
struct xive_q *q = &xc->queues[i];
/* Single escalation, no queue 7 */
if (i == 7 && kvmppc_xive_has_single_escalation(xive))
break;
/* Is queue already enabled ? Provision it */
if (xive->qmap & (1 << i)) {
r = xive_provision_queue(vcpu, i);
if (r == 0 && !kvmppc_xive_has_single_escalation(xive))
kvmppc_xive_attach_escalation(
vcpu, i, kvmppc_xive_has_single_escalation(xive));
if (r)
goto bail;
} else {
r = xive_native_configure_queue(xc->vp_id,
q, i, NULL, 0, true);
if (r) {
pr_err("Failed to configure queue %d for VCPU %d\n",
i, cpu);
goto bail;
}
}
}
/* If not done above, attach priority 0 escalation */
r = kvmppc_xive_attach_escalation(vcpu, 0, kvmppc_xive_has_single_escalation(xive));
if (r)
goto bail;
/* Route the IPI */
r = xive_native_configure_irq(xc->vp_ipi, xc->vp_id, 0, XICS_IPI);
if (!r)
xive_vm_esb_load(&xc->vp_ipi_data, XIVE_ESB_SET_PQ_00);
bail:
mutex_unlock(&xive->lock);
if (r) {
kvmppc_xive_cleanup_vcpu(vcpu);
return r;
}
vcpu->arch.irq_type = KVMPPC_IRQ_XICS;
return 0;
}
/*
* Scanning of queues before/after migration save
*/
static void xive_pre_save_set_queued(struct kvmppc_xive *xive, u32 irq)
{
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
u16 idx;
sb = kvmppc_xive_find_source(xive, irq, &idx);
if (!sb)
return;
state = &sb->irq_state[idx];
/* Some sanity checking */
if (!state->valid) {
pr_err("invalid irq 0x%x in cpu queue!\n", irq);
return;
}
/*
* If the interrupt is in a queue it should have P set.
* We warn so that gets reported. A backtrace isn't useful
* so no need to use a WARN_ON.
*/
if (!state->saved_p)
pr_err("Interrupt 0x%x is marked in a queue but P not set !\n", irq);
/* Set flag */
state->in_queue = true;
}
static void xive_pre_save_mask_irq(struct kvmppc_xive *xive,
struct kvmppc_xive_src_block *sb,
u32 irq)
{
struct kvmppc_xive_irq_state *state = &sb->irq_state[irq];
if (!state->valid)
return;
/* Mask and save state, this will also sync HW queues */
state->saved_scan_prio = xive_lock_and_mask(xive, sb, state);
/* Transfer P and Q */
state->saved_p = state->old_p;
state->saved_q = state->old_q;
/* Unlock */
arch_spin_unlock(&sb->lock);
}
static void xive_pre_save_unmask_irq(struct kvmppc_xive *xive,
struct kvmppc_xive_src_block *sb,
u32 irq)
{
struct kvmppc_xive_irq_state *state = &sb->irq_state[irq];
if (!state->valid)
return;
/*
* Lock / exclude EOI (not technically necessary if the
* guest isn't running concurrently. If this becomes a
* performance issue we can probably remove the lock.
*/
xive_lock_for_unmask(sb, state);
/* Restore mask/prio if it wasn't masked */
if (state->saved_scan_prio != MASKED)
xive_finish_unmask(xive, sb, state, state->saved_scan_prio);
/* Unlock */
arch_spin_unlock(&sb->lock);
}
static void xive_pre_save_queue(struct kvmppc_xive *xive, struct xive_q *q)
{
u32 idx = q->idx;
u32 toggle = q->toggle;
u32 irq;
do {
irq = __xive_read_eq(q->qpage, q->msk, &idx, &toggle);
if (irq > XICS_IPI)
xive_pre_save_set_queued(xive, irq);
} while(irq);
}
static void xive_pre_save_scan(struct kvmppc_xive *xive)
{
struct kvm_vcpu *vcpu = NULL;
unsigned long i;
int j;
/*
* See comment in xive_get_source() about how this
* work. Collect a stable state for all interrupts
*/
for (i = 0; i <= xive->max_sbid; i++) {
struct kvmppc_xive_src_block *sb = xive->src_blocks[i];
if (!sb)
continue;
for (j = 0; j < KVMPPC_XICS_IRQ_PER_ICS; j++)
xive_pre_save_mask_irq(xive, sb, j);
}
/* Then scan the queues and update the "in_queue" flag */
kvm_for_each_vcpu(i, vcpu, xive->kvm) {
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
if (!xc)
continue;
for (j = 0; j < KVMPPC_XIVE_Q_COUNT; j++) {
if (xc->queues[j].qpage)
xive_pre_save_queue(xive, &xc->queues[j]);
}
}
/* Finally restore interrupt states */
for (i = 0; i <= xive->max_sbid; i++) {
struct kvmppc_xive_src_block *sb = xive->src_blocks[i];
if (!sb)
continue;
for (j = 0; j < KVMPPC_XICS_IRQ_PER_ICS; j++)
xive_pre_save_unmask_irq(xive, sb, j);
}
}
static void xive_post_save_scan(struct kvmppc_xive *xive)
{
u32 i, j;
/* Clear all the in_queue flags */
for (i = 0; i <= xive->max_sbid; i++) {
struct kvmppc_xive_src_block *sb = xive->src_blocks[i];
if (!sb)
continue;
for (j = 0; j < KVMPPC_XICS_IRQ_PER_ICS; j++)
sb->irq_state[j].in_queue = false;
}
/* Next get_source() will do a new scan */
xive->saved_src_count = 0;
}
/*
* This returns the source configuration and state to user space.
*/
static int xive_get_source(struct kvmppc_xive *xive, long irq, u64 addr)
{
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
u64 __user *ubufp = (u64 __user *) addr;
u64 val, prio;
u16 idx;
sb = kvmppc_xive_find_source(xive, irq, &idx);
if (!sb)
return -ENOENT;
state = &sb->irq_state[idx];
if (!state->valid)
return -ENOENT;
pr_devel("get_source(%ld)...\n", irq);
/*
* So to properly save the state into something that looks like a
* XICS migration stream we cannot treat interrupts individually.
*
* We need, instead, mask them all (& save their previous PQ state)
* to get a stable state in the HW, then sync them to ensure that
* any interrupt that had already fired hits its queue, and finally
* scan all the queues to collect which interrupts are still present
* in the queues, so we can set the "pending" flag on them and
* they can be resent on restore.
*
* So we do it all when the "first" interrupt gets saved, all the
* state is collected at that point, the rest of xive_get_source()
* will merely collect and convert that state to the expected
* userspace bit mask.
*/
if (xive->saved_src_count == 0)
xive_pre_save_scan(xive);
xive->saved_src_count++;
/* Convert saved state into something compatible with xics */
val = state->act_server;
prio = state->saved_scan_prio;
if (prio == MASKED) {
val |= KVM_XICS_MASKED;
prio = state->saved_priority;
}
val |= prio << KVM_XICS_PRIORITY_SHIFT;
if (state->lsi) {
val |= KVM_XICS_LEVEL_SENSITIVE;
if (state->saved_p)
val |= KVM_XICS_PENDING;
} else {
if (state->saved_p)
val |= KVM_XICS_PRESENTED;
if (state->saved_q)
val |= KVM_XICS_QUEUED;
/*
* We mark it pending (which will attempt a re-delivery)
* if we are in a queue *or* we were masked and had
* Q set which is equivalent to the XICS "masked pending"
* state
*/
if (state->in_queue || (prio == MASKED && state->saved_q))
val |= KVM_XICS_PENDING;
}
/*
* If that was the last interrupt saved, reset the
* in_queue flags
*/
if (xive->saved_src_count == xive->src_count)
xive_post_save_scan(xive);
/* Copy the result to userspace */
if (put_user(val, ubufp))
return -EFAULT;
return 0;
}
struct kvmppc_xive_src_block *kvmppc_xive_create_src_block(
struct kvmppc_xive *xive, int irq)
{
struct kvmppc_xive_src_block *sb;
int i, bid;
bid = irq >> KVMPPC_XICS_ICS_SHIFT;
mutex_lock(&xive->lock);
/* block already exists - somebody else got here first */
if (xive->src_blocks[bid])
goto out;
/* Create the ICS */
sb = kzalloc(sizeof(*sb), GFP_KERNEL);
if (!sb)
goto out;
sb->id = bid;
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
sb->irq_state[i].number = (bid << KVMPPC_XICS_ICS_SHIFT) | i;
sb->irq_state[i].eisn = 0;
sb->irq_state[i].guest_priority = MASKED;
sb->irq_state[i].saved_priority = MASKED;
sb->irq_state[i].act_priority = MASKED;
}
smp_wmb();
xive->src_blocks[bid] = sb;
if (bid > xive->max_sbid)
xive->max_sbid = bid;
out:
mutex_unlock(&xive->lock);
return xive->src_blocks[bid];
}
static bool xive_check_delayed_irq(struct kvmppc_xive *xive, u32 irq)
{
struct kvm *kvm = xive->kvm;
struct kvm_vcpu *vcpu = NULL;
unsigned long i;
kvm_for_each_vcpu(i, vcpu, kvm) {
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
if (!xc)
continue;
if (xc->delayed_irq == irq) {
xc->delayed_irq = 0;
xive->delayed_irqs--;
return true;
}
}
return false;
}
static int xive_set_source(struct kvmppc_xive *xive, long irq, u64 addr)
{
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
u64 __user *ubufp = (u64 __user *) addr;
u16 idx;
u64 val;
u8 act_prio, guest_prio;
u32 server;
int rc = 0;
if (irq < KVMPPC_XICS_FIRST_IRQ || irq >= KVMPPC_XICS_NR_IRQS)
return -ENOENT;
pr_devel("set_source(irq=0x%lx)\n", irq);
/* Find the source */
sb = kvmppc_xive_find_source(xive, irq, &idx);
if (!sb) {
pr_devel("No source, creating source block...\n");
sb = kvmppc_xive_create_src_block(xive, irq);
if (!sb) {
pr_devel("Failed to create block...\n");
return -ENOMEM;
}
}
state = &sb->irq_state[idx];
/* Read user passed data */
if (get_user(val, ubufp)) {
pr_devel("fault getting user info !\n");
return -EFAULT;
}
server = val & KVM_XICS_DESTINATION_MASK;
guest_prio = val >> KVM_XICS_PRIORITY_SHIFT;
pr_devel(" val=0x016%llx (server=0x%x, guest_prio=%d)\n",
val, server, guest_prio);
/*
* If the source doesn't already have an IPI, allocate
* one and get the corresponding data
*/
if (!state->ipi_number) {
state->ipi_number = xive_native_alloc_irq();
if (state->ipi_number == 0) {
pr_devel("Failed to allocate IPI !\n");
return -ENOMEM;
}
xive_native_populate_irq_data(state->ipi_number, &state->ipi_data);
pr_devel(" src_ipi=0x%x\n", state->ipi_number);
}
/*
* We use lock_and_mask() to set us in the right masked
* state. We will override that state from the saved state
* further down, but this will handle the cases of interrupts
* that need FW masking. We set the initial guest_priority to
* 0 before calling it to ensure it actually performs the masking.
*/
state->guest_priority = 0;
xive_lock_and_mask(xive, sb, state);
/*
* Now, we select a target if we have one. If we don't we
* leave the interrupt untargetted. It means that an interrupt
* can become "untargetted" across migration if it was masked
* by set_xive() but there is little we can do about it.
*/
/* First convert prio and mark interrupt as untargetted */
act_prio = xive_prio_from_guest(guest_prio);
state->act_priority = MASKED;
/*
* We need to drop the lock due to the mutex below. Hopefully
* nothing is touching that interrupt yet since it hasn't been
* advertized to a running guest yet
*/
arch_spin_unlock(&sb->lock);
/* If we have a priority target the interrupt */
if (act_prio != MASKED) {
/* First, check provisioning of queues */
mutex_lock(&xive->lock);
rc = xive_check_provisioning(xive->kvm, act_prio);
mutex_unlock(&xive->lock);
/* Target interrupt */
if (rc == 0)
rc = xive_target_interrupt(xive->kvm, state,
server, act_prio);
/*
* If provisioning or targetting failed, leave it
* alone and masked. It will remain disabled until
* the guest re-targets it.
*/
}
/*
* Find out if this was a delayed irq stashed in an ICP,
* in which case, treat it as pending
*/
if (xive->delayed_irqs && xive_check_delayed_irq(xive, irq)) {
val |= KVM_XICS_PENDING;
pr_devel(" Found delayed ! forcing PENDING !\n");
}
/* Cleanup the SW state */
state->old_p = false;
state->old_q = false;
state->lsi = false;
state->asserted = false;
/* Restore LSI state */
if (val & KVM_XICS_LEVEL_SENSITIVE) {
state->lsi = true;
if (val & KVM_XICS_PENDING)
state->asserted = true;
pr_devel(" LSI ! Asserted=%d\n", state->asserted);
}
/*
* Restore P and Q. If the interrupt was pending, we
* force Q and !P, which will trigger a resend.
*
* That means that a guest that had both an interrupt
* pending (queued) and Q set will restore with only
* one instance of that interrupt instead of 2, but that
* is perfectly fine as coalescing interrupts that haven't
* been presented yet is always allowed.
*/
if (val & KVM_XICS_PRESENTED && !(val & KVM_XICS_PENDING))
state->old_p = true;
if (val & KVM_XICS_QUEUED || val & KVM_XICS_PENDING)
state->old_q = true;
pr_devel(" P=%d, Q=%d\n", state->old_p, state->old_q);
/*
* If the interrupt was unmasked, update guest priority and
* perform the appropriate state transition and do a
* re-trigger if necessary.
*/
if (val & KVM_XICS_MASKED) {
pr_devel(" masked, saving prio\n");
state->guest_priority = MASKED;
state->saved_priority = guest_prio;
} else {
pr_devel(" unmasked, restoring to prio %d\n", guest_prio);
xive_finish_unmask(xive, sb, state, guest_prio);
state->saved_priority = guest_prio;
}
/* Increment the number of valid sources and mark this one valid */
if (!state->valid)
xive->src_count++;
state->valid = true;
return 0;
}
int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
bool line_status)
{
struct kvmppc_xive *xive = kvm->arch.xive;
struct kvmppc_xive_src_block *sb;
struct kvmppc_xive_irq_state *state;
u16 idx;
if (!xive)
return -ENODEV;
sb = kvmppc_xive_find_source(xive, irq, &idx);
if (!sb)
return -EINVAL;
/* Perform locklessly .... (we need to do some RCUisms here...) */
state = &sb->irq_state[idx];
if (!state->valid)
return -EINVAL;
/* We don't allow a trigger on a passed-through interrupt */
if (state->pt_number)
return -EINVAL;
if ((level == 1 && state->lsi) || level == KVM_INTERRUPT_SET_LEVEL)
state->asserted = true;
else if (level == 0 || level == KVM_INTERRUPT_UNSET) {
state->asserted = false;
return 0;
}
/* Trigger the IPI */
xive_irq_trigger(&state->ipi_data);
return 0;
}
int kvmppc_xive_set_nr_servers(struct kvmppc_xive *xive, u64 addr)
{
u32 __user *ubufp = (u32 __user *) addr;
u32 nr_servers;
int rc = 0;
if (get_user(nr_servers, ubufp))
return -EFAULT;
pr_devel("%s nr_servers=%u\n", __func__, nr_servers);
if (!nr_servers || nr_servers > KVM_MAX_VCPU_IDS)
return -EINVAL;
mutex_lock(&xive->lock);
if (xive->vp_base != XIVE_INVALID_VP)
/* The VP block is allocated once and freed when the device
* is released. Better not allow to change its size since its
* used by connect_vcpu to validate vCPU ids are valid (eg,
* setting it back to a higher value could allow connect_vcpu
* to come up with a VP id that goes beyond the VP block, which
* is likely to cause a crash in OPAL).
*/
rc = -EBUSY;
else if (nr_servers > KVM_MAX_VCPUS)
/* We don't need more servers. Higher vCPU ids get packed
* down below KVM_MAX_VCPUS by kvmppc_pack_vcpu_id().
*/
xive->nr_servers = KVM_MAX_VCPUS;
else
xive->nr_servers = nr_servers;
mutex_unlock(&xive->lock);
return rc;
}
static int xive_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
struct kvmppc_xive *xive = dev->private;
/* We honor the existing XICS ioctl */
switch (attr->group) {
case KVM_DEV_XICS_GRP_SOURCES:
return xive_set_source(xive, attr->attr, attr->addr);
case KVM_DEV_XICS_GRP_CTRL:
switch (attr->attr) {
case KVM_DEV_XICS_NR_SERVERS:
return kvmppc_xive_set_nr_servers(xive, attr->addr);
}
}
return -ENXIO;
}
static int xive_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
struct kvmppc_xive *xive = dev->private;
/* We honor the existing XICS ioctl */
switch (attr->group) {
case KVM_DEV_XICS_GRP_SOURCES:
return xive_get_source(xive, attr->attr, attr->addr);
}
return -ENXIO;
}
static int xive_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
/* We honor the same limits as XICS, at least for now */
switch (attr->group) {
case KVM_DEV_XICS_GRP_SOURCES:
if (attr->attr >= KVMPPC_XICS_FIRST_IRQ &&
attr->attr < KVMPPC_XICS_NR_IRQS)
return 0;
break;
case KVM_DEV_XICS_GRP_CTRL:
switch (attr->attr) {
case KVM_DEV_XICS_NR_SERVERS:
return 0;
}
}
return -ENXIO;
}
static void kvmppc_xive_cleanup_irq(u32 hw_num, struct xive_irq_data *xd)
{
xive_vm_esb_load(xd, XIVE_ESB_SET_PQ_01);
xive_native_configure_irq(hw_num, 0, MASKED, 0);
}
void kvmppc_xive_free_sources(struct kvmppc_xive_src_block *sb)
{
int i;
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
struct kvmppc_xive_irq_state *state = &sb->irq_state[i];
if (!state->valid)
continue;
kvmppc_xive_cleanup_irq(state->ipi_number, &state->ipi_data);
xive_cleanup_irq_data(&state->ipi_data);
xive_native_free_irq(state->ipi_number);
/* Pass-through, cleanup too but keep IRQ hw data */
if (state->pt_number)
kvmppc_xive_cleanup_irq(state->pt_number, state->pt_data);
state->valid = false;
}
}
/*
* Called when device fd is closed. kvm->lock is held.
*/
static void kvmppc_xive_release(struct kvm_device *dev)
{
struct kvmppc_xive *xive = dev->private;
struct kvm *kvm = xive->kvm;
struct kvm_vcpu *vcpu;
unsigned long i;
pr_devel("Releasing xive device\n");
/*
* Since this is the device release function, we know that
* userspace does not have any open fd referring to the
* device. Therefore there can not be any of the device
* attribute set/get functions being executed concurrently,
* and similarly, the connect_vcpu and set/clr_mapped
* functions also cannot be being executed.
*/
debugfs_remove(xive->dentry);
/*
* We should clean up the vCPU interrupt presenters first.
*/
kvm_for_each_vcpu(i, vcpu, kvm) {
/*
* Take vcpu->mutex to ensure that no one_reg get/set ioctl
* (i.e. kvmppc_xive_[gs]et_icp) can be done concurrently.
* Holding the vcpu->mutex also means that the vcpu cannot
* be executing the KVM_RUN ioctl, and therefore it cannot
* be executing the XIVE push or pull code or accessing
* the XIVE MMIO regions.
*/
mutex_lock(&vcpu->mutex);
kvmppc_xive_cleanup_vcpu(vcpu);
mutex_unlock(&vcpu->mutex);
}
/*
* Now that we have cleared vcpu->arch.xive_vcpu, vcpu->arch.irq_type
* and vcpu->arch.xive_esc_[vr]addr on each vcpu, we are safe
* against xive code getting called during vcpu execution or
* set/get one_reg operations.
*/
kvm->arch.xive = NULL;
/* Mask and free interrupts */
for (i = 0; i <= xive->max_sbid; i++) {
if (xive->src_blocks[i])
kvmppc_xive_free_sources(xive->src_blocks[i]);
kfree(xive->src_blocks[i]);
xive->src_blocks[i] = NULL;
}
if (xive->vp_base != XIVE_INVALID_VP)
xive_native_free_vp_block(xive->vp_base);
/*
* A reference of the kvmppc_xive pointer is now kept under
* the xive_devices struct of the machine for reuse. It is
* freed when the VM is destroyed for now until we fix all the
* execution paths.
*/
kfree(dev);
}
/*
* When the guest chooses the interrupt mode (XICS legacy or XIVE
* native), the VM will switch of KVM device. The previous device will
* be "released" before the new one is created.
*
* Until we are sure all execution paths are well protected, provide a
* fail safe (transitional) method for device destruction, in which
* the XIVE device pointer is recycled and not directly freed.
*/
struct kvmppc_xive *kvmppc_xive_get_device(struct kvm *kvm, u32 type)
{
struct kvmppc_xive **kvm_xive_device = type == KVM_DEV_TYPE_XIVE ?
&kvm->arch.xive_devices.native :
&kvm->arch.xive_devices.xics_on_xive;
struct kvmppc_xive *xive = *kvm_xive_device;
if (!xive) {
xive = kzalloc(sizeof(*xive), GFP_KERNEL);
*kvm_xive_device = xive;
} else {
memset(xive, 0, sizeof(*xive));
}
return xive;
}
/*
* Create a XICS device with XIVE backend. kvm->lock is held.
*/
static int kvmppc_xive_create(struct kvm_device *dev, u32 type)
{
struct kvmppc_xive *xive;
struct kvm *kvm = dev->kvm;
pr_devel("Creating xive for partition\n");
/* Already there ? */
if (kvm->arch.xive)
return -EEXIST;
xive = kvmppc_xive_get_device(kvm, type);
if (!xive)
return -ENOMEM;
dev->private = xive;
xive->dev = dev;
xive->kvm = kvm;
mutex_init(&xive->lock);
/* We use the default queue size set by the host */
xive->q_order = xive_native_default_eq_shift();
if (xive->q_order < PAGE_SHIFT)
xive->q_page_order = 0;
else
xive->q_page_order = xive->q_order - PAGE_SHIFT;
/* VP allocation is delayed to the first call to connect_vcpu */
xive->vp_base = XIVE_INVALID_VP;
/* KVM_MAX_VCPUS limits the number of VMs to roughly 64 per sockets
* on a POWER9 system.
*/
xive->nr_servers = KVM_MAX_VCPUS;
if (xive_native_has_single_escalation())
xive->flags |= KVMPPC_XIVE_FLAG_SINGLE_ESCALATION;
if (xive_native_has_save_restore())
xive->flags |= KVMPPC_XIVE_FLAG_SAVE_RESTORE;
kvm->arch.xive = xive;
return 0;
}
int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
/* The VM should have configured XICS mode before doing XICS hcalls. */
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
switch (req) {
case H_XIRR:
return xive_vm_h_xirr(vcpu);
case H_CPPR:
return xive_vm_h_cppr(vcpu, kvmppc_get_gpr(vcpu, 4));
case H_EOI:
return xive_vm_h_eoi(vcpu, kvmppc_get_gpr(vcpu, 4));
case H_IPI:
return xive_vm_h_ipi(vcpu, kvmppc_get_gpr(vcpu, 4),
kvmppc_get_gpr(vcpu, 5));
case H_IPOLL:
return xive_vm_h_ipoll(vcpu, kvmppc_get_gpr(vcpu, 4));
case H_XIRR_X:
xive_vm_h_xirr(vcpu);
kvmppc_set_gpr(vcpu, 5, get_tb() + vc->tb_offset);
return H_SUCCESS;
}
return H_UNSUPPORTED;
}
EXPORT_SYMBOL_GPL(kvmppc_xive_xics_hcall);
int kvmppc_xive_debug_show_queues(struct seq_file *m, struct kvm_vcpu *vcpu)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
unsigned int i;
for (i = 0; i < KVMPPC_XIVE_Q_COUNT; i++) {
struct xive_q *q = &xc->queues[i];
u32 i0, i1, idx;
if (!q->qpage && !xc->esc_virq[i])
continue;
if (q->qpage) {
seq_printf(m, " q[%d]: ", i);
idx = q->idx;
i0 = be32_to_cpup(q->qpage + idx);
idx = (idx + 1) & q->msk;
i1 = be32_to_cpup(q->qpage + idx);
seq_printf(m, "T=%d %08x %08x...\n", q->toggle,
i0, i1);
}
if (xc->esc_virq[i]) {
struct irq_data *d = irq_get_irq_data(xc->esc_virq[i]);
struct xive_irq_data *xd =
irq_data_get_irq_handler_data(d);
u64 pq = xive_vm_esb_load(xd, XIVE_ESB_GET);
seq_printf(m, " ESC %d %c%c EOI @%llx",
xc->esc_virq[i],
(pq & XIVE_ESB_VAL_P) ? 'P' : '-',
(pq & XIVE_ESB_VAL_Q) ? 'Q' : '-',
xd->eoi_page);
seq_puts(m, "\n");
}
}
return 0;
}
void kvmppc_xive_debug_show_sources(struct seq_file *m,
struct kvmppc_xive_src_block *sb)
{
int i;
seq_puts(m, " LISN HW/CHIP TYPE PQ EISN CPU/PRIO\n");
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
struct kvmppc_xive_irq_state *state = &sb->irq_state[i];
struct xive_irq_data *xd;
u64 pq;
u32 hw_num;
if (!state->valid)
continue;
kvmppc_xive_select_irq(state, &hw_num, &xd);
pq = xive_vm_esb_load(xd, XIVE_ESB_GET);
seq_printf(m, "%08x %08x/%02x", state->number, hw_num,
xd->src_chip);
if (state->lsi)
seq_printf(m, " %cLSI", state->asserted ? '^' : ' ');
else
seq_puts(m, " MSI");
seq_printf(m, " %s %c%c %08x % 4d/%d",
state->ipi_number == hw_num ? "IPI" : " PT",
pq & XIVE_ESB_VAL_P ? 'P' : '-',
pq & XIVE_ESB_VAL_Q ? 'Q' : '-',
state->eisn, state->act_server,
state->act_priority);
seq_puts(m, "\n");
}
}
static int xive_debug_show(struct seq_file *m, void *private)
{
struct kvmppc_xive *xive = m->private;
struct kvm *kvm = xive->kvm;
struct kvm_vcpu *vcpu;
u64 t_rm_h_xirr = 0;
u64 t_rm_h_ipoll = 0;
u64 t_rm_h_cppr = 0;
u64 t_rm_h_eoi = 0;
u64 t_rm_h_ipi = 0;
u64 t_vm_h_xirr = 0;
u64 t_vm_h_ipoll = 0;
u64 t_vm_h_cppr = 0;
u64 t_vm_h_eoi = 0;
u64 t_vm_h_ipi = 0;
unsigned long i;
if (!kvm)
return 0;
seq_puts(m, "=========\nVCPU state\n=========\n");
kvm_for_each_vcpu(i, vcpu, kvm) {
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
if (!xc)
continue;
seq_printf(m, "VCPU %d: VP:%#x/%02x\n"
" CPPR:%#x HWCPPR:%#x MFRR:%#x PEND:%#x h_xirr: R=%lld V=%lld\n",
xc->server_num, xc->vp_id, xc->vp_chip_id,
xc->cppr, xc->hw_cppr,
xc->mfrr, xc->pending,
xc->stat_rm_h_xirr, xc->stat_vm_h_xirr);
kvmppc_xive_debug_show_queues(m, vcpu);
t_rm_h_xirr += xc->stat_rm_h_xirr;
t_rm_h_ipoll += xc->stat_rm_h_ipoll;
t_rm_h_cppr += xc->stat_rm_h_cppr;
t_rm_h_eoi += xc->stat_rm_h_eoi;
t_rm_h_ipi += xc->stat_rm_h_ipi;
t_vm_h_xirr += xc->stat_vm_h_xirr;
t_vm_h_ipoll += xc->stat_vm_h_ipoll;
t_vm_h_cppr += xc->stat_vm_h_cppr;
t_vm_h_eoi += xc->stat_vm_h_eoi;
t_vm_h_ipi += xc->stat_vm_h_ipi;
}
seq_puts(m, "Hcalls totals\n");
seq_printf(m, " H_XIRR R=%10lld V=%10lld\n", t_rm_h_xirr, t_vm_h_xirr);
seq_printf(m, " H_IPOLL R=%10lld V=%10lld\n", t_rm_h_ipoll, t_vm_h_ipoll);
seq_printf(m, " H_CPPR R=%10lld V=%10lld\n", t_rm_h_cppr, t_vm_h_cppr);
seq_printf(m, " H_EOI R=%10lld V=%10lld\n", t_rm_h_eoi, t_vm_h_eoi);
seq_printf(m, " H_IPI R=%10lld V=%10lld\n", t_rm_h_ipi, t_vm_h_ipi);
seq_puts(m, "=========\nSources\n=========\n");
for (i = 0; i <= xive->max_sbid; i++) {
struct kvmppc_xive_src_block *sb = xive->src_blocks[i];
if (sb) {
arch_spin_lock(&sb->lock);
kvmppc_xive_debug_show_sources(m, sb);
arch_spin_unlock(&sb->lock);
}
}
return 0;
}
DEFINE_SHOW_ATTRIBUTE(xive_debug);
static void xive_debugfs_init(struct kvmppc_xive *xive)
{
xive->dentry = debugfs_create_file("xive", S_IRUGO, xive->kvm->debugfs_dentry,
xive, &xive_debug_fops);
pr_debug("%s: created\n", __func__);
}
static void kvmppc_xive_init(struct kvm_device *dev)
{
struct kvmppc_xive *xive = dev->private;
/* Register some debug interfaces */
xive_debugfs_init(xive);
}
struct kvm_device_ops kvm_xive_ops = {
.name = "kvm-xive",
.create = kvmppc_xive_create,
.init = kvmppc_xive_init,
.release = kvmppc_xive_release,
.set_attr = xive_set_attr,
.get_attr = xive_get_attr,
.has_attr = xive_has_attr,
};