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@xxxxxxxxxx>
Co-developed-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
Signed-off-by: Oliver Upton <oupton@xxxxxxxxxx>
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
Reviewed-by: Peter Shier <pshier@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index f9ae7bc0a421..ecdc706f171b 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -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.
@@ -3867,8 +3877,8 @@ 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,
- vmcs12->host_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
27.5.2 Loading Host Segment and Descriptor-Table Registers */
--
2.24.0.rc1.363.gb1bccd3e3d-goog
