linux-zen-desktop/arch/x86/coco/tdx/tdx-shared.c

72 lines
1.5 KiB
C

#include <asm/tdx.h>
#include <asm/pgtable.h>
static unsigned long try_accept_one(phys_addr_t start, unsigned long len,
enum pg_level pg_level)
{
unsigned long accept_size = page_level_size(pg_level);
u64 tdcall_rcx;
u8 page_size;
if (!IS_ALIGNED(start, accept_size))
return 0;
if (len < accept_size)
return 0;
/*
* Pass the page physical address to the TDX module to accept the
* pending, private page.
*
* Bits 2:0 of RCX encode page size: 0 - 4K, 1 - 2M, 2 - 1G.
*/
switch (pg_level) {
case PG_LEVEL_4K:
page_size = 0;
break;
case PG_LEVEL_2M:
page_size = 1;
break;
case PG_LEVEL_1G:
page_size = 2;
break;
default:
return 0;
}
tdcall_rcx = start | page_size;
if (__tdx_module_call(TDX_ACCEPT_PAGE, tdcall_rcx, 0, 0, 0, NULL))
return 0;
return accept_size;
}
bool tdx_accept_memory(phys_addr_t start, phys_addr_t end)
{
/*
* For shared->private conversion, accept the page using
* TDX_ACCEPT_PAGE TDX module call.
*/
while (start < end) {
unsigned long len = end - start;
unsigned long accept_size;
/*
* Try larger accepts first. It gives chance to VMM to keep
* 1G/2M Secure EPT entries where possible and speeds up
* process by cutting number of hypercalls (if successful).
*/
accept_size = try_accept_one(start, len, PG_LEVEL_1G);
if (!accept_size)
accept_size = try_accept_one(start, len, PG_LEVEL_2M);
if (!accept_size)
accept_size = try_accept_one(start, len, PG_LEVEL_4K);
if (!accept_size)
return false;
start += accept_size;
}
return true;
}