Re: [PATCH v8 3/3] x86, apicv: add virtual x2apic support

Gleb Natapov
2013-01-07T07:07:26Z

On Mon, Jan 07, 2013 at 06:58:15AM +0000, Zhang, Yang Z wrote:
> Gleb Natapov wrote on 2013-01-07:
> > On Mon, Jan 07, 2013 at 10:02:37AM +0800, Yang Zhang wrote:
> >> From: Yang Zhang <yang.z.zhang@Intel.com>
> >>
> >> basically to benefit from apicv, we need clear MSR bitmap for
> >> corresponding x2apic MSRs when guest enabled x2apic:
> >> 0x800 - 0x8ff: no read intercept for apicv register virtualization
> >> TPR,EOI,SELF-IPI: no write intercept for virtual interrupt delivery
> >> Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
> >> Signed-off-by: Kevin Tian <kevin.tian@intel.com>
> >> ---
> >> arch/x86/include/asm/kvm_host.h | 1 + arch/x86/include/asm/vmx.h
> >> | 1 + arch/x86/kvm/lapic.c | 2 + arch/x86/kvm/svm.c
> >> | 6 +++ arch/x86/kvm/vmx.c | 80
> >> +++++++++++++++++++++++++++++++++++--- 5 files changed, 83
> >> insertions(+), 7 deletions(-)
> >> diff --git a/arch/x86/include/asm/kvm_host.h
> >> b/arch/x86/include/asm/kvm_host.h index 135603f..af9a8c3 100644 ---
> >> a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h
> >> @@ -704,6 +704,7 @@ struct kvm_x86_ops {
> >> void (*update_exitmap_end)(struct kvm_vcpu *vcpu); void
> >> (*load_eoi_exitmap)(struct kvm_vcpu *vcpu); void
> >> (*restore_rvi)(struct kvm_vcpu *vcpu); + void
> >> (*enable_virtual_x2apic_mode)(struct kvm_vcpu *vcpu); int
> >> (*set_tss_addr)(struct kvm *kvm, unsigned int addr); int
> >> (*get_tdp_level)(void); u64 (*get_mt_mask)(struct kvm_vcpu *vcpu,
> >> gfn_t gfn, bool is_mmio);
> >> diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
> >> index d1ab331..694586c 100644
> >> --- a/arch/x86/include/asm/vmx.h
> >> +++ b/arch/x86/include/asm/vmx.h
> >> @@ -140,6 +140,7 @@
> >> #define SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES 0x00000001 #define
> >> SECONDARY_EXEC_ENABLE_EPT 0x00000002 #define
> >> SECONDARY_EXEC_RDTSCP 0x00000008 +#define
> >> SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE 0x00000010 #define
> >> SECONDARY_EXEC_ENABLE_VPID 0x00000020 #define
> >> SECONDARY_EXEC_WBINVD_EXITING 0x00000040 #define
> >> SECONDARY_EXEC_UNRESTRICTED_GUEST 0x00000080
> >> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> >> index e1baf37..dba5300 100644
> >> --- a/arch/x86/kvm/lapic.c
> >> +++ b/arch/x86/kvm/lapic.c
> >> @@ -1349,6 +1349,8 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64
> > value)
> >> u32 id = kvm_apic_id(apic);
> >> u32 ldr = ((id >> 4) << 16) | (1 << (id & 0xf));
> >> kvm_apic_set_ldr(apic, ldr);
> >> + kvm_x86_ops->enable_virtual_x2apic_mode(vcpu);
> > And where do you disable it?
> Yes, need to disable it when guest rolls back to xapic mode. Will add it in next patch.
>
You also need to reorder patches 2 and 3. Otherwise x2apic will be
broken after patch 2.

--
Gleb.