Commit 2e6e0d68 authored by Xiaoyao Li's avatar Xiaoyao Li Committed by Paolo Bonzini

KVM: VMX: Restore host's MSR_IA32_RTIT_CTL when it's not zero

A minor optimization to WRMSR MSR_IA32_RTIT_CTL when necessary.

Opportunistically refine the comment to call out that KVM requires
VM_EXIT_CLEAR_IA32_RTIT_CTL to expose PT to the guest.
Reviewed-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarXiaoyao Li <xiaoyao.li@intel.com>
Message-Id: <20210827070249.924633-2-xiaoyao.li@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 2839180c
......@@ -1074,8 +1074,12 @@ static void pt_guest_exit(struct vcpu_vmx *vmx)
pt_load_msr(&vmx->pt_desc.host, vmx->pt_desc.addr_range);
}
/* Reload host state (IA32_RTIT_CTL will be cleared on VM exit). */
wrmsrl(MSR_IA32_RTIT_CTL, vmx->pt_desc.host.ctl);
/*
* KVM requires VM_EXIT_CLEAR_IA32_RTIT_CTL to expose PT to the guest,
* i.e. RTIT_CTL is always cleared on VM-Exit. Restore it if necessary.
*/
if (vmx->pt_desc.host.ctl)
wrmsrl(MSR_IA32_RTIT_CTL, vmx->pt_desc.host.ctl);
}
void vmx_set_host_fs_gs(struct vmcs_host_state *host, u16 fs_sel, u16 gs_sel,
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment