Commit 1e293d1a authored by Oliver Upton's avatar Oliver Upton Committed by Paolo Bonzini
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kvm: x86: request masterclock update any time guest uses different msr 



Commit 5b9bb0eb ("kvm: x86: encapsulate wrmsr(MSR_KVM_SYSTEM_TIME)
emulation in helper fn", 2020-10-21) subtly changed the behavior of guest
writes to MSR_KVM_SYSTEM_TIME(_NEW). Restore the previous behavior; update
the masterclock any time the guest uses a different msr than before.

Fixes: 5b9bb0eb ("kvm: x86: encapsulate wrmsr(MSR_KVM_SYSTEM_TIME) emulation in helper fn", 2020-10-21)
Signed-off-by: default avatarOliver Upton <oupton@google.com>
Reviewed-by: default avatarPeter Shier <pshier@google.com>
Message-Id: <20201027231044.655110-6-oupton@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 01b4f510

arch/x86/kvm/x86.c

+1 −1
Original line number Diff line number Diff line
@@ -1967,7 +1967,7 @@ static void kvm_write_system_time(struct kvm_vcpu *vcpu, gpa_t system_time, 
	struct kvm_arch *ka = &vcpu->kvm->arch;



	if (vcpu->vcpu_id == 0 && !host_initiated) {

		if (ka->boot_vcpu_runs_old_kvmclock && old_msr)

		if (ka->boot_vcpu_runs_old_kvmclock != old_msr)

			kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);



		ka->boot_vcpu_runs_old_kvmclock = old_msr;