Commit 458151f6 authored Nov 13, 2019 by Oliver Upton Committed by Paolo Bonzini Nov 15, 2019

KVM: nVMX: Use kvm_set_msr to load IA32_PERF_GLOBAL_CTRL on VM-Exit



The existing implementation for loading the IA32_PERF_GLOBAL_CTRL MSR
on VM-exit was incorrect, as the next call to atomic_switch_perf_msrs()
could cause this value to be overwritten. Instead, call kvm_set_msr()
which will allow atomic_switch_perf_msrs() to correctly set the values.

Define a macro, SET_MSR_OR_WARN(), to set the MSR with kvm_set_msr()
and WARN on failure.

Suggested-by: Jim Mattson <jmattson@google.com>
Co-developed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent c547cb6f

arch/x86/kvm/vmx/nested.c

+12 −2

Original line number	Diff line number	Diff line
		@@ -28,6 +28,16 @@ module_param(nested_early_check, bool, S_IRUGO);
		failed; \
		})

		#define SET_MSR_OR_WARN(vcpu, idx, data) \
		({ \
		bool failed = kvm_set_msr(vcpu, idx, data); \
		if (failed) \
		pr_warn_ratelimited( \
		"%s cannot write MSR (0x%x, 0x%llx)\n", \
		__func__, idx, data); \
		failed; \
		})

		/*
		* Hyper-V requires all of these, so mark them as supported even though
		* they are just treated the same as all-context.
		@@ -3879,7 +3889,7 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
		vcpu->arch.pat = vmcs12->host_ia32_pat;
		}
		if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
		vmcs_write64(GUEST_IA32_PERF_GLOBAL_CTRL,
		SET_MSR_OR_WARN(vcpu, MSR_CORE_PERF_GLOBAL_CTRL,
		vmcs12->host_ia32_perf_global_ctrl);

		/* Set L1 segment info according to Intel SDM

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