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KVM: x86: implement MSR_IA32_TSX_CTRL effect on CPUID

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Because KVM always emulates CPUID, the CPUID clear bit
(bit 1) of MSR_IA32_TSX_CTRL must be emulated "manually"
by the hypervisor when performing said emulation.

Right now neither kvm-intel.ko nor kvm-amd.ko implement
MSR_IA32_TSX_CTRL but this will change in the next patch.

Reviewed-by: Jim Mattson <jmattson@google.com>
Tested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2019-11-18 12:23:00 -05:00
parent de1fca5d6e
commit edef5c36b0
3 changed files with 9 additions and 4 deletions
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1
arch/x86/include/asm/kvm_host.h
View File

@ -1357,6 +1357,7 @@ int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu,
void kvm_enable_efer_bits(u64);
bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer);
int __kvm_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data, bool host_initiated);
int kvm_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data);
int kvm_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data);
int kvm_emulate_rdmsr(struct kvm_vcpu *vcpu);

8
arch/x86/kvm/cpuid.c
View File

@ -816,8 +816,6 @@ static int do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 func,
return __do_cpuid_func(entry, func, nent, maxnent);
}
#undef F
struct kvm_cpuid_param {
u32 func;
bool (*qualifier)(const struct kvm_cpuid_param *param);
@ -1015,6 +1013,12 @@ bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
*ebx = entry->ebx;
*ecx = entry->ecx;
*edx = entry->edx;
if (function == 7 && index == 0) {
u64 data;
if (!__kvm_get_msr(vcpu, MSR_IA32_TSX_CTRL, &data, true) &&
(data & TSX_CTRL_CPUID_CLEAR))
*ebx &= ~(F(RTM) | F(HLE));
}
} else {
*eax = *ebx = *ecx = *edx = 0;
/*

4
arch/x86/kvm/x86.c
View File

@ -1484,8 +1484,8 @@ static int __kvm_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data,
* Returns 0 on success, non-0 otherwise.
* Assumes vcpu_load() was already called.
*/
static int __kvm_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data,
bool host_initiated)
int __kvm_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data,
bool host_initiated)
{
struct msr_data msr;
int ret;