Commit edef5c36 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: x86: implement MSR_IA32_TSX_CTRL effect on CPUID 



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: default avatarJim Mattson <jmattson@google.com>
Tested-by: default avatarJim Mattson <jmattson@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent de1fca5d

arch/x86/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

arch/x86/kvm/cpuid.c

+6 −2
Original line number Diff line number Diff line
@@ -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;

		/*

arch/x86/kvm/x86.c

+2 −2
Original line number Diff line number Diff line
@@ -1484,7 +1484,7 @@ 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,

int __kvm_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data,

		  bool host_initiated)

{

	struct msr_data msr;

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