[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 1/2] x86: flush high xstate CPUID sub-leaves to zero
In line with other recent changes, these should be fully white listed, requiring us to zero them until the obtain a meaning we support. Without XSAVE support, all xstate sub-leaves should be zero. Also move away from checking host XSAVE support - we really ought to consider the guest flag for that purpose. Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -3433,7 +3433,13 @@ void hvm_cpuid(unsigned int input, unsig *edx = v->vcpu_id * 2; break; - case 0xd: + case XSTATE_CPUID: + hvm_cpuid(1, NULL, NULL, &_ecx, NULL); + if ( !(_ecx & cpufeat_mask(X86_FEATURE_XSAVE)) || count >= 63 ) + { + *eax = *ebx = *ecx = *edx = 0; + break; + } /* EBX value of main leaf 0 depends on enabled xsave features */ if ( count == 0 && v->arch.xcr0 ) { --- a/xen/arch/x86/traps.c +++ b/xen/arch/x86/traps.c @@ -928,6 +928,8 @@ void pv_cpuid(struct cpu_user_regs *regs switch ( leaf ) { + uint32_t tmp; + case 0x00000001: c &= pv_featureset[FEATURESET_1c]; d &= pv_featureset[FEATURESET_1d]; @@ -1085,14 +1087,19 @@ void pv_cpuid(struct cpu_user_regs *regs break; case XSTATE_CPUID: - if ( !cpu_has_xsave ) + if ( !((!is_control_domain(currd) && !is_hardware_domain(currd) + ? ({ + uint32_t ecx; + + domain_cpuid(currd, 1, 0, &tmp, &tmp, &ecx, &tmp); + ecx & pv_featureset[FEATURESET_1c]; + }) + : cpuid_ecx(1)) & cpufeat_mask(X86_FEATURE_XSAVE)) || + subleaf >= 63 ) goto unsupported; switch ( subleaf ) { case 0: - { - uint32_t tmp; - /* * Always read CPUID.0xD[ECX=0].EBX from hardware, rather than * domain policy. It varies with enabled xstate, and the correct @@ -1101,7 +1108,6 @@ void pv_cpuid(struct cpu_user_regs *regs if ( !is_control_domain(currd) && !is_hardware_domain(currd) ) cpuid_count(leaf, subleaf, &tmp, &b, &tmp, &tmp); break; - } case 1: a &= pv_featureset[FEATURESET_Da1]; Attachment:
x86-xstate-CPUID-high-leaves.patch _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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