hvf: Guard xgetbv call

This prevents illegal instruction on cpus that do not support xgetbv.

Buglink: https://bugs.launchpad.net/qemu/+bug/1758819
Reviewed-by: Cameron Esfahani <dirty@apple.com>
Signed-off-by: Hill Ma <maahiuzeon@gmail.com>
Message-Id: <X/6OJ7qk0W6bHkHQ@Hills-Mac-Pro.local>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Hill Ma 2021-01-12 22:07:35 -08:00 committed by Paolo Bonzini
parent 342e3a4f20
commit 118f2aadbc
1 changed files with 22 additions and 12 deletions

View File

@ -27,15 +27,22 @@
#include "vmx.h"
#include "sysemu/hvf.h"
static uint64_t xgetbv(uint32_t xcr)
static bool xgetbv(uint32_t cpuid_ecx, uint32_t idx, uint64_t *xcr)
{
uint32_t eax, edx;
uint32_t xcrl, xcrh;
__asm__ volatile ("xgetbv"
: "=a" (eax), "=d" (edx)
: "c" (xcr));
if (cpuid_ecx & CPUID_EXT_OSXSAVE) {
/*
* The xgetbv instruction is not available to older versions of
* the assembler, so we encode the instruction manually.
*/
asm(".byte 0x0f, 0x01, 0xd0" : "=a" (xcrl), "=d" (xcrh) : "c" (idx));
return (((uint64_t)edx) << 32) | eax;
*xcr = (((uint64_t)xcrh) << 32) | xcrl;
return true;
}
return false;
}
uint32_t hvf_get_supported_cpuid(uint32_t func, uint32_t idx,
@ -100,12 +107,15 @@ uint32_t hvf_get_supported_cpuid(uint32_t func, uint32_t idx,
break;
case 0xD:
if (idx == 0) {
uint64_t host_xcr0 = xgetbv(0);
uint64_t supp_xcr0 = host_xcr0 & (XSTATE_FP_MASK | XSTATE_SSE_MASK |
XSTATE_YMM_MASK | XSTATE_BNDREGS_MASK |
XSTATE_BNDCSR_MASK | XSTATE_OPMASK_MASK |
XSTATE_ZMM_Hi256_MASK | XSTATE_Hi16_ZMM_MASK);
eax &= supp_xcr0;
uint64_t host_xcr0;
if (xgetbv(ecx, 0, &host_xcr0)) {
uint64_t supp_xcr0 = host_xcr0 & (XSTATE_FP_MASK |
XSTATE_SSE_MASK | XSTATE_YMM_MASK |
XSTATE_BNDREGS_MASK | XSTATE_BNDCSR_MASK |
XSTATE_OPMASK_MASK | XSTATE_ZMM_Hi256_MASK |
XSTATE_Hi16_ZMM_MASK);
eax &= supp_xcr0;
}
} else if (idx == 1) {
hv_vmx_read_capability(HV_VMX_CAP_PROCBASED2, &cap);
eax &= CPUID_XSAVE_XSAVEOPT | CPUID_XSAVE_XGETBV1;