From: Wenyao Hai Date: Thu, 11 May 2023 23:33:44 +0000 (-0700) Subject: KVM: VMX: Open code writing vCPU's PAT in VMX's MSR handler X-Git-Tag: v6.6.17~4463^2~5^2~18 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a33ba1bf0dc6082227d1ddf964632e07b53b8971;p=platform%2Fkernel%2Flinux-rpi.git KVM: VMX: Open code writing vCPU's PAT in VMX's MSR handler Open code setting "vcpu->arch.pat" in vmx_set_msr() instead of bouncing through kvm_set_msr_common() to get to the same code in kvm_mtrr_set_msr(). This aligns VMX with SVM, avoids hiding a very simple operation behind a relatively complicated function call (finding the PAT MSR case in kvm_set_msr_common() is non-trivial), and most importantly, makes it clear that not unwinding the VMCS updates if kvm_set_msr_common() isn't a bug (because kvm_set_msr_common() can never fail for PAT). Opportunistically set vcpu->arch.pat before updating the VMCS info so that a future patch can move the common bits (back) into kvm_set_msr_common() without a functional change. Note, MSR_IA32_CR_PAT is 0x277, and is very subtly handled by case 0x200 ... MSR_IA32_MC0_CTL2 - 1: in kvm_set_msr_common(). Cc: Kai Huang Signed-off-by: Wenyao Hai [sean: massage changelog, hoist setting vcpu->arch.pat up] Reviewed-by: Kai Huang Link: https://lore.kernel.org/r/20230511233351.635053-2-seanjc@google.com Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 44fb619..33b8625 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2290,16 +2290,14 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (!kvm_pat_valid(data)) return 1; + vcpu->arch.pat = data; + if (is_guest_mode(vcpu) && get_vmcs12(vcpu)->vm_exit_controls & VM_EXIT_SAVE_IA32_PAT) get_vmcs12(vcpu)->guest_ia32_pat = data; - if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) { + if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) vmcs_write64(GUEST_IA32_PAT, data); - vcpu->arch.pat = data; - break; - } - ret = kvm_set_msr_common(vcpu, msr_info); break; case MSR_IA32_MCG_EXT_CTL: if ((!msr_info->host_initiated &&