> -----Original Message----- > From: Paolo Bonzini [mailto:paolo.bonzini@xxxxxxxxx] On Behalf Of Paolo Bonzini > Sent: Friday, January 5, 2018 11:43 PM > To: linux-kernel@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx > Cc: Kang, Luwei <luwei.kang@xxxxxxxxx> > Subject: [PATCH] KVM: VMX: use same MSR bitmaps for 32-/64-bit modes, fix MSR bitmaps for processor tracing > > KVM has a small optimization where it doesn't save/restore MSR_KERNEL_GS_BASE if the guest is in 32-bit mode. However, this > complicates the code noticeably by doubling the number of possible MSR bitmaps. In addition, pt_disable_intercept_for_msr was > only updating the "basic" MSR bitmap, because x2apic and x2apic_apicv are memcpy'd just once in hardware_setup. > > Remove the long-mode bitmaps set, and touch all the three remaining bitmaps in vmx_disable_intercept_for_msr and > vmx_enable_intercept_for_msr. > > Fixes: 3bd1f85e893daec4f3982d1d45b6bfc0683442c4 > Cc: Luwei Kang <luwei.kang@xxxxxxxxx> > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > --- > arch/x86/kvm/vmx.c | 126 ++++++++++++++++++++--------------------------------- > 1 file changed, 48 insertions(+), 78 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 11321cc4129a..ea5b52dc2d78 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -935,12 +935,9 @@ static bool nested_vmx_is_page_fault_vmexit(struct vmcs12 *vmcs12, static > DEFINE_PER_CPU(spinlock_t, blocked_vcpu_on_cpu_lock); > > enum { > - VMX_MSR_BITMAP_LEGACY, > - VMX_MSR_BITMAP_LONGMODE, > - VMX_MSR_BITMAP_LEGACY_X2APIC_APICV, > - VMX_MSR_BITMAP_LONGMODE_X2APIC_APICV, > - VMX_MSR_BITMAP_LEGACY_X2APIC, > - VMX_MSR_BITMAP_LONGMODE_X2APIC, > + VMX_MSR_BITMAP_NOX2APIC, > + VMX_MSR_BITMAP_X2APIC_APICV, > + VMX_MSR_BITMAP_X2APIC, > VMX_VMREAD_BITMAP, > VMX_VMWRITE_BITMAP, > VMX_BITMAP_NR > @@ -948,12 +945,9 @@ enum { > > static unsigned long *vmx_bitmap[VMX_BITMAP_NR]; > > -#define vmx_msr_bitmap_legacy (vmx_bitmap[VMX_MSR_BITMAP_LEGACY]) > -#define vmx_msr_bitmap_longmode (vmx_bitmap[VMX_MSR_BITMAP_LONGMODE]) > -#define vmx_msr_bitmap_legacy_x2apic_apicv (vmx_bitmap[VMX_MSR_BITMAP_LEGACY_X2APIC_APICV]) > -#define vmx_msr_bitmap_longmode_x2apic_apicv (vmx_bitmap[VMX_MSR_BITMAP_LONGMODE_X2APIC_APICV]) > -#define vmx_msr_bitmap_legacy_x2apic (vmx_bitmap[VMX_MSR_BITMAP_LEGACY_X2APIC]) > -#define vmx_msr_bitmap_longmode_x2apic (vmx_bitmap[VMX_MSR_BITMAP_LONGMODE_X2APIC]) > +#define vmx_msr_bitmap_nox2apic (vmx_bitmap[VMX_MSR_BITMAP_NOX2APIC]) > +#define vmx_msr_bitmap_x2apic_apicv (vmx_bitmap[VMX_MSR_BITMAP_X2APIC_APICV]) > +#define vmx_msr_bitmap_x2apic (vmx_bitmap[VMX_MSR_BITMAP_X2APIC]) > #define vmx_vmread_bitmap (vmx_bitmap[VMX_VMREAD_BITMAP]) > #define vmx_vmwrite_bitmap (vmx_bitmap[VMX_VMWRITE_BITMAP]) > > @@ -2203,8 +2197,7 @@ static void vmx_save_host_state(struct kvm_vcpu *vcpu) > > #ifdef CONFIG_X86_64 > rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base); > - if (is_long_mode(&vmx->vcpu)) > - wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base); > + wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base); > #endif > if (boot_cpu_has(X86_FEATURE_MPX)) > rdmsrl(MSR_IA32_BNDCFGS, vmx->host_state.msr_host_bndcfgs); > @@ -2222,8 +2215,7 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx) > ++vmx->vcpu.stat.host_state_reload; > vmx->host_state.loaded = 0; > #ifdef CONFIG_X86_64 > - if (is_long_mode(&vmx->vcpu)) > - rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base); > + rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base); > #endif > if (vmx->host_state.gs_ldt_reload_needed) { > kvm_load_ldt(vmx->host_state.ldt_sel); > @@ -2635,21 +2627,12 @@ static void vmx_set_msr_bitmap(struct kvm_vcpu *vcpu) > (vmcs_read32(SECONDARY_VM_EXEC_CONTROL) & > SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE)) { > if (enable_apicv && kvm_vcpu_apicv_active(vcpu)) { > - if (is_long_mode(vcpu)) > - msr_bitmap = vmx_msr_bitmap_longmode_x2apic_apicv; > - else > - msr_bitmap = vmx_msr_bitmap_legacy_x2apic_apicv; > + msr_bitmap = vmx_msr_bitmap_x2apic_apicv; > } else { > - if (is_long_mode(vcpu)) > - msr_bitmap = vmx_msr_bitmap_longmode_x2apic; > - else > - msr_bitmap = vmx_msr_bitmap_legacy_x2apic; > + msr_bitmap = vmx_msr_bitmap_x2apic; > } > } else { > - if (is_long_mode(vcpu)) > - msr_bitmap = vmx_msr_bitmap_longmode; > - else > - msr_bitmap = vmx_msr_bitmap_legacy; > + msr_bitmap = vmx_msr_bitmap_nox2apic; > } > > vmcs_write64(MSR_BITMAP, __pa(msr_bitmap)); @@ -5211,22 +5194,24 @@ static void > nested_vmx_disable_intercept_for_msr(unsigned long *msr_bitmap_l1, > } > } > > -static void vmx_disable_intercept_for_msr(u32 msr, bool longmode_only) > +static void vmx_disable_intercept_for_msr(u32 msr) > { > - if (!longmode_only) > - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy, > - msr, MSR_TYPE_R | MSR_TYPE_W); > - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode, > - msr, MSR_TYPE_R | MSR_TYPE_W); > + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_nox2apic, > + msr, MSR_TYPE_R | MSR_TYPE_W); > + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_x2apic, > + msr, MSR_TYPE_R | MSR_TYPE_W); > + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_x2apic_apicv, > + msr, MSR_TYPE_R | MSR_TYPE_W); > } > > -static void vmx_enable_intercept_for_msr(u32 msr, bool longmode_only) > +static void vmx_enable_intercept_for_msr(u32 msr) > { > - if (!longmode_only) > - __vmx_enable_intercept_for_msr(vmx_msr_bitmap_legacy, > - msr, MSR_TYPE_R | MSR_TYPE_W); > - __vmx_enable_intercept_for_msr(vmx_msr_bitmap_longmode, > - msr, MSR_TYPE_R | MSR_TYPE_W); > + __vmx_enable_intercept_for_msr(vmx_msr_bitmap_nox2apic, > + msr, MSR_TYPE_R | MSR_TYPE_W); > + __vmx_enable_intercept_for_msr(vmx_msr_bitmap_x2apic, > + msr, MSR_TYPE_R | MSR_TYPE_W); > + __vmx_enable_intercept_for_msr(vmx_msr_bitmap_x2apic_apicv, > + msr, MSR_TYPE_R | MSR_TYPE_W); > } > > static void pt_disable_intercept_for_msr(bool flag) @@ -5235,36 +5220,29 @@ static void pt_disable_intercept_for_msr(bool > flag) > unsigned int addr_num = kvm_get_pt_addr_cnt(); > > if (flag) { > - vmx_disable_intercept_for_msr(MSR_IA32_RTIT_STATUS, false); > - vmx_disable_intercept_for_msr(MSR_IA32_RTIT_OUTPUT_BASE, false); > - vmx_disable_intercept_for_msr(MSR_IA32_RTIT_OUTPUT_MASK, false); > - vmx_disable_intercept_for_msr(MSR_IA32_RTIT_CR3_MATCH, false); > + vmx_disable_intercept_for_msr(MSR_IA32_RTIT_STATUS); > + vmx_disable_intercept_for_msr(MSR_IA32_RTIT_OUTPUT_BASE); > + vmx_disable_intercept_for_msr(MSR_IA32_RTIT_OUTPUT_MASK); > + vmx_disable_intercept_for_msr(MSR_IA32_RTIT_CR3_MATCH); > for (i = 0; i < addr_num; i++) > - vmx_disable_intercept_for_msr(MSR_IA32_RTIT_ADDR0_A + i, > - false); > + vmx_disable_intercept_for_msr(MSR_IA32_RTIT_ADDR0_A + i); > } else { > - vmx_enable_intercept_for_msr(MSR_IA32_RTIT_STATUS, false); > - vmx_enable_intercept_for_msr(MSR_IA32_RTIT_OUTPUT_BASE, false); > - vmx_enable_intercept_for_msr(MSR_IA32_RTIT_OUTPUT_MASK, false); > - vmx_enable_intercept_for_msr(MSR_IA32_RTIT_CR3_MATCH, false); > + vmx_enable_intercept_for_msr(MSR_IA32_RTIT_STATUS); > + vmx_enable_intercept_for_msr(MSR_IA32_RTIT_OUTPUT_BASE); > + vmx_enable_intercept_for_msr(MSR_IA32_RTIT_OUTPUT_MASK); > + vmx_enable_intercept_for_msr(MSR_IA32_RTIT_CR3_MATCH); > for (i = 0; i < addr_num; i++) > - vmx_enable_intercept_for_msr(MSR_IA32_RTIT_ADDR0_A + i, > - false); > + vmx_enable_intercept_for_msr(MSR_IA32_RTIT_ADDR0_A + i); > } > } > > static void vmx_disable_intercept_msr_x2apic(u32 msr, int type, bool apicv_only) { > - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic_apicv, > + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_x2apic_apicv, > msr, type); > - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic_apicv, > - msr, type); > - if (!apicv_only) { > - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_legacy_x2apic, > - msr, type); > - __vmx_disable_intercept_for_msr(vmx_msr_bitmap_longmode_x2apic, > + if (!apicv_only) > + __vmx_disable_intercept_for_msr(vmx_msr_bitmap_x2apic, > msr, type); > - } > } > > static bool vmx_get_enable_apicv(struct kvm_vcpu *vcpu) @@ -5733,7 +5711,7 @@ static void vmx_vcpu_setup(struct > vcpu_vmx *vmx) > vmcs_write64(VMWRITE_BITMAP, __pa(vmx_vmwrite_bitmap)); > } > if (cpu_has_vmx_msr_bitmap()) > - vmcs_write64(MSR_BITMAP, __pa(vmx_msr_bitmap_legacy)); > + vmcs_write64(MSR_BITMAP, __pa(vmx_msr_bitmap_nox2apic)); > > vmcs_write64(VMCS_LINK_POINTER, -1ull); /* 22.3.1.5 */ > > @@ -7047,8 +7025,9 @@ static __init int hardware_setup(void) > memset(vmx_vmread_bitmap, 0xff, PAGE_SIZE); > memset(vmx_vmwrite_bitmap, 0xff, PAGE_SIZE); > > - memset(vmx_msr_bitmap_legacy, 0xff, PAGE_SIZE); > - memset(vmx_msr_bitmap_longmode, 0xff, PAGE_SIZE); > + memset(vmx_msr_bitmap_nox2apic, 0xff, PAGE_SIZE); > + memset(vmx_msr_bitmap_x2apic, 0xff, PAGE_SIZE); > + memset(vmx_msr_bitmap_x2apic_apicv, 0xff, PAGE_SIZE); > > if (setup_vmcs_config(&vmcs_config) < 0) { > r = -EIO; > @@ -7113,21 +7092,12 @@ static __init int hardware_setup(void) > kvm_tsc_scaling_ratio_frac_bits = 48; > } > > - vmx_disable_intercept_for_msr(MSR_FS_BASE, false); > - vmx_disable_intercept_for_msr(MSR_GS_BASE, false); > - vmx_disable_intercept_for_msr(MSR_KERNEL_GS_BASE, true); > - vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_CS, false); > - vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_ESP, false); > - vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_EIP, false); > - > - memcpy(vmx_msr_bitmap_legacy_x2apic_apicv, > - vmx_msr_bitmap_legacy, PAGE_SIZE); > - memcpy(vmx_msr_bitmap_longmode_x2apic_apicv, > - vmx_msr_bitmap_longmode, PAGE_SIZE); > - memcpy(vmx_msr_bitmap_legacy_x2apic, > - vmx_msr_bitmap_legacy, PAGE_SIZE); > - memcpy(vmx_msr_bitmap_longmode_x2apic, > - vmx_msr_bitmap_longmode, PAGE_SIZE); > + vmx_disable_intercept_for_msr(MSR_FS_BASE); > + vmx_disable_intercept_for_msr(MSR_GS_BASE); > + vmx_disable_intercept_for_msr(MSR_KERNEL_GS_BASE); > + vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_CS); > + vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_ESP); > + vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_EIP); > > set_bit(0, vmx_vpid_bitmap); /* 0 is reserved for host */ > Reviewed-by: Luwei Kang <luwei.kang@xxxxxxxxx> Thanks, Luwei Kang
