From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Oliver Upton <oupton@google.com>
Cc: kvm@vger.kernel.org, "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Jim Mattson" <jmattson@google.com>,
"Peter Shier" <pshier@google.com>,
"Krish Sadhukhan" <krish.sadhukhan@oracle.com>
Subject: Re: [PATCH v4 1/9] KVM: nVMX: Use kvm_set_msr to load IA32_PERF_GLOBAL_CTRL on vmexit
Date: Mon, 16 Sep 2019 11:03:45 -0700 [thread overview]
Message-ID: <20190916180345.GE18871@linux.intel.com> (raw)
In-Reply-To: <20190906210313.128316-2-oupton@google.com>
On Fri, Sep 06, 2019 at 02:03:05PM -0700, Oliver Upton wrote:
> 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.
>
> 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>
> ---
> arch/x86/kvm/vmx/nested.c | 13 ++++++++++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index ced9fba32598..b0ca34bf4d21 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -3724,6 +3724,7 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
> struct vmcs12 *vmcs12)
> {
> struct kvm_segment seg;
> + struct msr_data msr_info;
> u32 entry_failure_code;
>
> if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_EFER)
> @@ -3800,9 +3801,15 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
> vmcs_write64(GUEST_IA32_PAT, vmcs12->host_ia32_pat);
> 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);
> + if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL) {
> + msr_info.host_initiated = false;
> + msr_info.index = MSR_CORE_PERF_GLOBAL_CTRL;
> + msr_info.data = vmcs12->host_ia32_perf_global_ctrl;
> + if (kvm_set_msr(vcpu, &msr_info))
> + pr_debug_ratelimited(
> + "%s cannot write MSR (0x%x, 0x%llx)\n",
> + __func__, msr_info.index, msr_info.data);
Since this is for a single MSR, we should print the human-readable name of
the MSR as well as its index, e.g.:
pr_debug_ratelimited(
"%s cannot write PERF_GLOBAL_CONTROL MSR (0x%x, 0x%llx)\n",
> + }
>
> /* Set L1 segment info according to Intel SDM
> 27.5.2 Loading Host Segment and Descriptor-Table Registers */
> --
> 2.23.0.187.g17f5b7556c-goog
>
next prev parent reply other threads:[~2019-09-16 18:03 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-06 21:03 [PATCH v4 0/9] KVM: VMX: Add full nested support for IA32_PERF_GLOBAL_CTRL Oliver Upton
2019-09-06 21:03 ` [PATCH v4 1/9] KVM: nVMX: Use kvm_set_msr to load IA32_PERF_GLOBAL_CTRL on vmexit Oliver Upton
2019-09-16 18:03 ` Sean Christopherson [this message]
2019-09-16 18:15 ` Sean Christopherson
2019-09-06 21:03 ` [PATCH v4 2/9] KVM: nVMX: Load GUEST_IA32_PERF_GLOBAL_CTRL MSR on vm-entry Oliver Upton
2019-09-16 18:06 ` Sean Christopherson
2019-09-16 21:17 ` Oliver Upton
2019-09-16 22:50 ` Sean Christopherson
2019-09-06 21:03 ` [PATCH v4 3/9] KVM: VMX: Add helper to check reserved bits in IA32_PERF_GLOBAL_CTRL Oliver Upton
2019-09-06 21:03 ` [PATCH v4 4/9] KVM: nVMX: check GUEST_IA32_PERF_GLOBAL_CTRL on VM-Entry Oliver Upton
2019-09-16 18:10 ` Sean Christopherson
2019-09-16 21:19 ` Oliver Upton
2019-09-06 21:03 ` [PATCH v4 5/9] KVM: nVMX: Check HOST_IA32_PERF_GLOBAL_CTRL on VM-entry Oliver Upton
2019-09-16 18:10 ` Sean Christopherson
2019-09-06 21:03 ` [PATCH v4 6/9] KVM: nVMX: Expose load IA32_PERF_GLOBAL_CTRL vm control if supported Oliver Upton
2019-09-16 18:27 ` Sean Christopherson
2019-09-06 21:03 ` [kvm-unit-test PATCH v4 7/9] vmx: Allow vmx_tests to reset the test_guest_func Oliver Upton
2019-09-10 20:49 ` Krish Sadhukhan
2019-09-06 21:03 ` [kvm-unit-tests PATCH v4 8/9] x86: VMX: Make guest_state_test_main() check state from nested VM Oliver Upton
2019-09-10 20:51 ` Krish Sadhukhan
2019-09-06 21:03 ` [kvm-unit-tests PATCH v4 9/9] x86: VMX: Add tests for nested "load IA32_PERF_GLOBAL_CTRL" Oliver Upton
2019-09-12 16:28 ` Krish Sadhukhan
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