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| author | Hill Ma <maahiuzeon@gmail.com> | 2021-01-12 22:07:35 -0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-02-16 17:15:39 +0100 |
| commit | 118f2aadbc66aaae4e8d52259288e18f2aa4544a (patch) | |
| tree | 7ce0e4a57f36fb0262ee4d091b231beb50a91735 /target | |
| parent | 342e3a4f20653c2d419cc0e8fdc0b99dfea32fed (diff) | |
| download | qemu-118f2aadbc66aaae4e8d52259288e18f2aa4544a.zip qemu-118f2aadbc66aaae4e8d52259288e18f2aa4544a.tar.gz qemu-118f2aadbc66aaae4e8d52259288e18f2aa4544a.tar.bz2 | |
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>
Diffstat (limited to 'target')
| -rw-r--r-- | target/i386/hvf/x86_cpuid.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/target/i386/hvf/x86_cpuid.c b/target/i386/hvf/x86_cpuid.c index a684291..32b0d13 100644 --- a/target/i386/hvf/x86_cpuid.c +++ b/target/i386/hvf/x86_cpuid.c @@ -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; |