From f6e90f9e0ee3df5010e7f378e669d6838b9a25bf Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Thu, 22 Sep 2016 07:43:25 +0800 Subject: [PATCH] KVM: VMX: Enable MSR-BASED TPR shadow even if APICv is inactive MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit I observed that kvmvapic(to optimize flexpriority=N or AMD) is used to boost TPR access when testing kvm-unit-test/eventinj.flat tpr case on my haswell desktop (w/ flexpriority, w/o APICv). Commit (8d14695f9542 x86, apicv: add virtual x2apic support) disable virtual x2apic mode completely if w/o APICv, and the author also told me that windows guest can't enter into x2apic mode when he developed the APICv feature several years ago. However, it is not truth currently, Interrupt Remapping and vIOMMU is added to qemu and the developers from Intel test windows 8 can work in x2apic mode w/ Interrupt Remapping enabled recently. This patch enables TPR shadow for virtual x2apic mode to boost windows guest in x2apic mode even if w/o APICv. Can pass the kvm-unit-test. Suggested-by: Radim Krčmář Suggested-by: Wincy Van Reviewed-by: Radim Krčmář Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Wincy Van Cc: Yang Zhang Signed-off-by: Wanpeng Li Signed-off-by: Radim Krčmář --- arch/x86/kvm/vmx.c | 132 ++++++++++++++++++++++++++++++++------------- 1 file changed, 94 insertions(+), 38 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 122047a5409c..5a5ab2062cb5 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -927,6 +927,8 @@ static unsigned long *vmx_msr_bitmap_legacy; static unsigned long *vmx_msr_bitmap_longmode; static unsigned long *vmx_msr_bitmap_legacy_x2apic; static unsigned long *vmx_msr_bitmap_longmode_x2apic; +static unsigned long *vmx_msr_bitmap_legacy_x2apic_apicv_inactive; +static unsigned long *vmx_msr_bitmap_longmode_x2apic_apicv_inactive; static unsigned long *vmx_vmread_bitmap; static unsigned long *vmx_vmwrite_bitmap; @@ -2524,10 +2526,17 @@ static void vmx_set_msr_bitmap(struct kvm_vcpu *vcpu) else if (cpu_has_secondary_exec_ctrls() && (vmcs_read32(SECONDARY_VM_EXEC_CONTROL) & SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE)) { - if (is_long_mode(vcpu)) - msr_bitmap = vmx_msr_bitmap_longmode_x2apic; - else - msr_bitmap = vmx_msr_bitmap_legacy_x2apic; + if (enable_apicv && kvm_vcpu_apicv_active(vcpu)) { + if (is_long_mode(vcpu)) + msr_bitmap = vmx_msr_bitmap_longmode_x2apic; + else + msr_bitmap = vmx_msr_bitmap_legacy_x2apic; + } else { + if (is_long_mode(vcpu)) + msr_bitmap = vmx_msr_bitmap_longmode_x2apic_apicv_inactive; + else + msr_bitmap = vmx_msr_bitmap_legacy_x2apic_apicv_inactive; + } } else { if (is_long_mode(vcpu)) msr_bitmap = vmx_msr_bitmap_longmode; @@ -4682,28 +4691,49 @@ static void vmx_disable_intercept_for_msr(u32 msr, bool longmode_only) msr, MSR_TYPE_R | MSR_TYPE_W); } -static void vmx_enable_intercept_msr_read_x2apic(u32 msr) +static void vmx_enable_intercept_msr_read_x2apic(u32 msr, bool apicv_active) { - __vmx_enable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic, - msr, MSR_TYPE_R); - __vmx_enable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic, - msr, MSR_TYPE_R); + if (apicv_active) { + __vmx_enable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic, + msr, MSR_TYPE_R); + __vmx_enable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic, + msr, MSR_TYPE_R); + } else { + __vmx_enable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic_apicv_inactive, + msr, MSR_TYPE_R); + __vmx_enable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic_apicv_inactive, + msr, MSR_TYPE_R); + } } -static void vmx_disable_intercept_msr_read_x2apic(u32 msr) +static void vmx_disable_intercept_msr_read_x2apic(u32 msr, bool apicv_active) { - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic, - msr, MSR_TYPE_R); - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic, - msr, MSR_TYPE_R); + if (apicv_active) { + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic, + msr, MSR_TYPE_R); + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic, + msr, MSR_TYPE_R); + } else { + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic_apicv_inactive, + msr, MSR_TYPE_R); + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic_apicv_inactive, + msr, MSR_TYPE_R); + } } -static void vmx_disable_intercept_msr_write_x2apic(u32 msr) +static void vmx_disable_intercept_msr_write_x2apic(u32 msr, bool apicv_active) { - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic, - msr, MSR_TYPE_W); - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic, - msr, MSR_TYPE_W); + if (apicv_active) { + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic, + msr, MSR_TYPE_W); + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic, + msr, MSR_TYPE_W); + } else { + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic_apicv_inactive, + msr, MSR_TYPE_W); + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic_apicv_inactive, + msr, MSR_TYPE_W); + } } static bool vmx_get_enable_apicv(void) @@ -6364,22 +6394,32 @@ static __init int hardware_setup(void) if (!vmx_msr_bitmap_legacy_x2apic) goto out2; + vmx_msr_bitmap_legacy_x2apic_apicv_inactive = + (unsigned long *)__get_free_page(GFP_KERNEL); + if (!vmx_msr_bitmap_legacy_x2apic_apicv_inactive) + goto out3; + vmx_msr_bitmap_longmode = (unsigned long *)__get_free_page(GFP_KERNEL); if (!vmx_msr_bitmap_longmode) - goto out3; + goto out4; vmx_msr_bitmap_longmode_x2apic = (unsigned long *)__get_free_page(GFP_KERNEL); if (!vmx_msr_bitmap_longmode_x2apic) - goto out4; + goto out5; + + vmx_msr_bitmap_longmode_x2apic_apicv_inactive = + (unsigned long *)__get_free_page(GFP_KERNEL); + if (!vmx_msr_bitmap_longmode_x2apic_apicv_inactive) + goto out6; vmx_vmread_bitmap = (unsigned long *)__get_free_page(GFP_KERNEL); if (!vmx_vmread_bitmap) - goto out6; + goto out7; vmx_vmwrite_bitmap = (unsigned long *)__get_free_page(GFP_KERNEL); if (!vmx_vmwrite_bitmap) - goto out7; + goto out8; memset(vmx_vmread_bitmap, 0xff, PAGE_SIZE); memset(vmx_vmwrite_bitmap, 0xff, PAGE_SIZE); @@ -6398,7 +6438,7 @@ static __init int hardware_setup(void) if (setup_vmcs_config(&vmcs_config) < 0) { r = -EIO; - goto out8; + goto out9; } if (boot_cpu_has(X86_FEATURE_NX)) @@ -6465,20 +6505,35 @@ static __init int hardware_setup(void) vmx_msr_bitmap_legacy, PAGE_SIZE); memcpy(vmx_msr_bitmap_longmode_x2apic, vmx_msr_bitmap_longmode, PAGE_SIZE); + memcpy(vmx_msr_bitmap_legacy_x2apic_apicv_inactive, + vmx_msr_bitmap_legacy, PAGE_SIZE); + memcpy(vmx_msr_bitmap_longmode_x2apic_apicv_inactive, + vmx_msr_bitmap_longmode, PAGE_SIZE); set_bit(0, vmx_vpid_bitmap); /* 0 is reserved for host */ + /* + * enable_apicv && kvm_vcpu_apicv_active() + */ for (msr = 0x800; msr <= 0x8ff; msr++) - vmx_disable_intercept_msr_read_x2apic(msr); + vmx_disable_intercept_msr_read_x2apic(msr, true); /* TMCCT */ - vmx_enable_intercept_msr_read_x2apic(0x839); + vmx_enable_intercept_msr_read_x2apic(0x839, true); /* TPR */ - vmx_disable_intercept_msr_write_x2apic(0x808); + vmx_disable_intercept_msr_write_x2apic(0x808, true); /* EOI */ - vmx_disable_intercept_msr_write_x2apic(0x80b); + vmx_disable_intercept_msr_write_x2apic(0x80b, true); /* SELF-IPI */ - vmx_disable_intercept_msr_write_x2apic(0x83f); + vmx_disable_intercept_msr_write_x2apic(0x83f, true); + + /* + * (enable_apicv && !kvm_vcpu_apicv_active()) || + * !enable_apicv + */ + /* TPR */ + vmx_disable_intercept_msr_read_x2apic(0x808, false); + vmx_disable_intercept_msr_write_x2apic(0x808, false); if (enable_ept) { kvm_mmu_set_mask_ptes(VMX_EPT_READABLE_MASK, @@ -6525,14 +6580,18 @@ static __init int hardware_setup(void) return alloc_kvm_area(); -out8: +out9: free_page((unsigned long)vmx_vmwrite_bitmap); -out7: +out8: free_page((unsigned long)vmx_vmread_bitmap); +out7: + free_page((unsigned long)vmx_msr_bitmap_longmode_x2apic_apicv_inactive); out6: free_page((unsigned long)vmx_msr_bitmap_longmode_x2apic); -out4: +out5: free_page((unsigned long)vmx_msr_bitmap_longmode); +out4: + free_page((unsigned long)vmx_msr_bitmap_legacy_x2apic_apicv_inactive); out3: free_page((unsigned long)vmx_msr_bitmap_legacy_x2apic); out2: @@ -6548,7 +6607,9 @@ out: static __exit void hardware_unsetup(void) { free_page((unsigned long)vmx_msr_bitmap_legacy_x2apic); + free_page((unsigned long)vmx_msr_bitmap_legacy_x2apic_apicv_inactive); free_page((unsigned long)vmx_msr_bitmap_longmode_x2apic); + free_page((unsigned long)vmx_msr_bitmap_longmode_x2apic_apicv_inactive); free_page((unsigned long)vmx_msr_bitmap_legacy); free_page((unsigned long)vmx_msr_bitmap_longmode); free_page((unsigned long)vmx_io_bitmap_b); @@ -8439,12 +8500,7 @@ static void vmx_set_virtual_x2apic_mode(struct kvm_vcpu *vcpu, bool set) return; } - /* - * There is not point to enable virtualize x2apic without enable - * apicv - */ - if (!cpu_has_vmx_virtualize_x2apic_mode() || - !kvm_vcpu_apicv_active(vcpu)) + if (!cpu_has_vmx_virtualize_x2apic_mode()) return; if (!cpu_need_tpr_shadow(vcpu)) -- 2.20.1