| Message ID | ea9057ece714a919664e0403a3e7f774e4b3fedf.1699368363.git.isaku.yamahata@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM TDX: TDP MMU: large page support | expand |
On 11/7/2023 11:00 PM, isaku.yamahata@intel.com wrote: > From: Xiaoyao Li <xiaoyao.li@intel.com> > > For TDX, EPT violation can happen when TDG.MEM.PAGE.ACCEPT. > And TDG.MEM.PAGE.ACCEPT contains the desired accept page level of TD guest. > > 1. KVM can map it with 4KB page while TD guest wants to accept 2MB page. > > TD geust will get TDX_PAGE_SIZE_MISMATCH and it should try to accept s/geust/guest > 4KB size. > > 2. KVM can map it with 2MB page while TD guest wants to accept 4KB page. > > KVM needs to honor it because > a) there is no way to tell guest KVM maps it as 2MB size. And > b) guest accepts it in 4KB size since guest knows some other 4KB page > in the same 2MB range will be used as shared page. > > For case 2, it need to pass desired page level to MMU's > page_fault_handler. Use bit 29:31 of kvm PF error code for this purpose. The level info is needed not only for case 2, KVM also needs the info so that it can map a 2MB page when TD guest wants to accept a 2MB page. > > Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > --- > arch/x86/include/asm/kvm_host.h | 3 +++ > arch/x86/kvm/mmu/mmu.c | 5 +++++ > arch/x86/kvm/vmx/common.h | 6 +++++- > arch/x86/kvm/vmx/tdx.c | 15 ++++++++++++++- > arch/x86/kvm/vmx/tdx.h | 19 +++++++++++++++++++ > arch/x86/kvm/vmx/vmx.c | 2 +- > 6 files changed, 47 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index edcafcd650db..eed36c1eedb7 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -261,6 +261,8 @@ enum x86_intercept_stage; > #define PFERR_FETCH_BIT 4 > #define PFERR_PK_BIT 5 > #define PFERR_SGX_BIT 15 > +#define PFERR_LEVEL_START_BIT 29 > +#define PFERR_LEVEL_END_BIT 31 > #define PFERR_GUEST_FINAL_BIT 32 > #define PFERR_GUEST_PAGE_BIT 33 > #define PFERR_GUEST_ENC_BIT 34 > @@ -273,6 +275,7 @@ enum x86_intercept_stage; > #define PFERR_FETCH_MASK BIT(PFERR_FETCH_BIT) > #define PFERR_PK_MASK BIT(PFERR_PK_BIT) > #define PFERR_SGX_MASK BIT(PFERR_SGX_BIT) > +#define PFERR_LEVEL_MASK GENMASK_ULL(PFERR_LEVEL_END_BIT, PFERR_LEVEL_START_BIT) > #define PFERR_GUEST_FINAL_MASK BIT_ULL(PFERR_GUEST_FINAL_BIT) > #define PFERR_GUEST_PAGE_MASK BIT_ULL(PFERR_GUEST_PAGE_BIT) > #define PFERR_GUEST_ENC_MASK BIT_ULL(PFERR_GUEST_ENC_BIT) > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index eb17a508c5d1..265177cedf37 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -4615,6 +4615,11 @@ bool __kvm_mmu_honors_guest_mtrrs(bool vm_has_noncoherent_dma) > > int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) > { > + u8 err_level = (fault->error_code & PFERR_LEVEL_MASK) >> PFERR_LEVEL_START_BIT; > + > + if (err_level) > + fault->max_level = min(fault->max_level, err_level); > + > /* > * If the guest's MTRRs may be used to compute the "real" memtype, > * restrict the mapping level to ensure KVM uses a consistent memtype > diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h > index 027aa4175d2c..bb00433932ee 100644 > --- a/arch/x86/kvm/vmx/common.h > +++ b/arch/x86/kvm/vmx/common.h > @@ -67,7 +67,8 @@ static inline void vmx_handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu, > } > > static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa, > - unsigned long exit_qualification) > + unsigned long exit_qualification, > + int err_page_level) > { > u64 error_code; > > @@ -90,6 +91,9 @@ static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa, > if (kvm_is_private_gpa(vcpu->kvm, gpa)) > error_code |= PFERR_GUEST_ENC_MASK; > > + if (err_page_level > 0) > + error_code |= (err_page_level << PFERR_LEVEL_START_BIT) & PFERR_LEVEL_MASK; > + > return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0); > } > > diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c > index 31598b84811f..e4167f08b58b 100644 > --- a/arch/x86/kvm/vmx/tdx.c > +++ b/arch/x86/kvm/vmx/tdx.c > @@ -1803,7 +1803,20 @@ void tdx_deliver_interrupt(struct kvm_lapic *apic, int delivery_mode, > > static int tdx_handle_ept_violation(struct kvm_vcpu *vcpu) > { > + union tdx_ext_exit_qualification ext_exit_qual; > unsigned long exit_qual; > + int err_page_level = 0; > + > + ext_exit_qual.full = tdexit_ext_exit_qual(vcpu); > + > + if (ext_exit_qual.type >= NUM_EXT_EXIT_QUAL) { Can we add unlikely() hint here? > + pr_err("EPT violation at gpa 0x%lx, with invalid ext exit qualification type 0x%x\n", > + tdexit_gpa(vcpu), ext_exit_qual.type); > + kvm_vm_bugged(vcpu->kvm); > + return 0; > + } else if (ext_exit_qual.type == EXT_EXIT_QUAL_ACCEPT) { > + err_page_level = tdx_sept_level_to_pg_level(ext_exit_qual.req_sept_level); > + } > > if (kvm_is_private_gpa(vcpu->kvm, tdexit_gpa(vcpu))) { > /* > @@ -1830,7 +1843,7 @@ static int tdx_handle_ept_violation(struct kvm_vcpu *vcpu) > } > > trace_kvm_page_fault(vcpu, tdexit_gpa(vcpu), exit_qual); > - return __vmx_handle_ept_violation(vcpu, tdexit_gpa(vcpu), exit_qual); > + return __vmx_handle_ept_violation(vcpu, tdexit_gpa(vcpu), exit_qual, err_page_level); > } > > static int tdx_handle_ept_misconfig(struct kvm_vcpu *vcpu) > diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h > index 54c3f6b83571..37ee944c36a1 100644 > --- a/arch/x86/kvm/vmx/tdx.h > +++ b/arch/x86/kvm/vmx/tdx.h > @@ -72,6 +72,25 @@ union tdx_exit_reason { > u64 full; > }; > > +union tdx_ext_exit_qualification { > + struct { > + u64 type : 4; > + u64 reserved0 : 28; > + u64 req_sept_level : 3; > + u64 err_sept_level : 3; > + u64 err_sept_state : 8; > + u64 err_sept_is_leaf : 1; > + u64 reserved1 : 17; > + }; > + u64 full; > +}; > + > +enum tdx_ext_exit_qualification_type { > + EXT_EXIT_QUAL_NONE, > + EXT_EXIT_QUAL_ACCEPT, > + NUM_EXT_EXIT_QUAL, > +}; > + > struct vcpu_tdx { > struct kvm_vcpu vcpu; > > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 28732925792e..ae9ba0731521 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -5753,7 +5753,7 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu) > if (unlikely(allow_smaller_maxphyaddr && kvm_vcpu_is_illegal_gpa(vcpu, gpa))) > return kvm_emulate_instruction(vcpu, 0); > > - return __vmx_handle_ept_violation(vcpu, gpa, exit_qualification); > + return __vmx_handle_ept_violation(vcpu, gpa, exit_qualification, 0); > } > > static int handle_ept_misconfig(struct kvm_vcpu *vcpu)
On Mon, Nov 20, 2023 at 06:54:07PM +0800, Binbin Wu <binbin.wu@linux.intel.com> wrote: > > > On 11/7/2023 11:00 PM, isaku.yamahata@intel.com wrote: > > From: Xiaoyao Li <xiaoyao.li@intel.com> > > > > For TDX, EPT violation can happen when TDG.MEM.PAGE.ACCEPT. > > And TDG.MEM.PAGE.ACCEPT contains the desired accept page level of TD guest. > > > > 1. KVM can map it with 4KB page while TD guest wants to accept 2MB page. > > > > TD geust will get TDX_PAGE_SIZE_MISMATCH and it should try to accept > s/geust/guest > > > 4KB size. > > > > 2. KVM can map it with 2MB page while TD guest wants to accept 4KB page. > > > > KVM needs to honor it because > > a) there is no way to tell guest KVM maps it as 2MB size. And > > b) guest accepts it in 4KB size since guest knows some other 4KB page > > in the same 2MB range will be used as shared page. > > > > For case 2, it need to pass desired page level to MMU's > > page_fault_handler. Use bit 29:31 of kvm PF error code for this purpose. > > The level info is needed not only for case 2, KVM also needs the info so > that > it can map a 2MB page when TD guest wants to accept a 2MB page. "MMU's page_fault_handler" = KVM MMU page fault handler, isn't it? I'll replace it with KVM MMU page fault handler for clarity.
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index edcafcd650db..eed36c1eedb7 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -261,6 +261,8 @@ enum x86_intercept_stage; #define PFERR_FETCH_BIT 4 #define PFERR_PK_BIT 5 #define PFERR_SGX_BIT 15 +#define PFERR_LEVEL_START_BIT 29 +#define PFERR_LEVEL_END_BIT 31 #define PFERR_GUEST_FINAL_BIT 32 #define PFERR_GUEST_PAGE_BIT 33 #define PFERR_GUEST_ENC_BIT 34 @@ -273,6 +275,7 @@ enum x86_intercept_stage; #define PFERR_FETCH_MASK BIT(PFERR_FETCH_BIT) #define PFERR_PK_MASK BIT(PFERR_PK_BIT) #define PFERR_SGX_MASK BIT(PFERR_SGX_BIT) +#define PFERR_LEVEL_MASK GENMASK_ULL(PFERR_LEVEL_END_BIT, PFERR_LEVEL_START_BIT) #define PFERR_GUEST_FINAL_MASK BIT_ULL(PFERR_GUEST_FINAL_BIT) #define PFERR_GUEST_PAGE_MASK BIT_ULL(PFERR_GUEST_PAGE_BIT) #define PFERR_GUEST_ENC_MASK BIT_ULL(PFERR_GUEST_ENC_BIT) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index eb17a508c5d1..265177cedf37 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4615,6 +4615,11 @@ bool __kvm_mmu_honors_guest_mtrrs(bool vm_has_noncoherent_dma) int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) { + u8 err_level = (fault->error_code & PFERR_LEVEL_MASK) >> PFERR_LEVEL_START_BIT; + + if (err_level) + fault->max_level = min(fault->max_level, err_level); + /* * If the guest's MTRRs may be used to compute the "real" memtype, * restrict the mapping level to ensure KVM uses a consistent memtype diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h index 027aa4175d2c..bb00433932ee 100644 --- a/arch/x86/kvm/vmx/common.h +++ b/arch/x86/kvm/vmx/common.h @@ -67,7 +67,8 @@ static inline void vmx_handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu, } static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa, - unsigned long exit_qualification) + unsigned long exit_qualification, + int err_page_level) { u64 error_code; @@ -90,6 +91,9 @@ static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa, if (kvm_is_private_gpa(vcpu->kvm, gpa)) error_code |= PFERR_GUEST_ENC_MASK; + if (err_page_level > 0) + error_code |= (err_page_level << PFERR_LEVEL_START_BIT) & PFERR_LEVEL_MASK; + return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0); } diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 31598b84811f..e4167f08b58b 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1803,7 +1803,20 @@ void tdx_deliver_interrupt(struct kvm_lapic *apic, int delivery_mode, static int tdx_handle_ept_violation(struct kvm_vcpu *vcpu) { + union tdx_ext_exit_qualification ext_exit_qual; unsigned long exit_qual; + int err_page_level = 0; + + ext_exit_qual.full = tdexit_ext_exit_qual(vcpu); + + if (ext_exit_qual.type >= NUM_EXT_EXIT_QUAL) { + pr_err("EPT violation at gpa 0x%lx, with invalid ext exit qualification type 0x%x\n", + tdexit_gpa(vcpu), ext_exit_qual.type); + kvm_vm_bugged(vcpu->kvm); + return 0; + } else if (ext_exit_qual.type == EXT_EXIT_QUAL_ACCEPT) { + err_page_level = tdx_sept_level_to_pg_level(ext_exit_qual.req_sept_level); + } if (kvm_is_private_gpa(vcpu->kvm, tdexit_gpa(vcpu))) { /* @@ -1830,7 +1843,7 @@ static int tdx_handle_ept_violation(struct kvm_vcpu *vcpu) } trace_kvm_page_fault(vcpu, tdexit_gpa(vcpu), exit_qual); - return __vmx_handle_ept_violation(vcpu, tdexit_gpa(vcpu), exit_qual); + return __vmx_handle_ept_violation(vcpu, tdexit_gpa(vcpu), exit_qual, err_page_level); } static int tdx_handle_ept_misconfig(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h index 54c3f6b83571..37ee944c36a1 100644 --- a/arch/x86/kvm/vmx/tdx.h +++ b/arch/x86/kvm/vmx/tdx.h @@ -72,6 +72,25 @@ union tdx_exit_reason { u64 full; }; +union tdx_ext_exit_qualification { + struct { + u64 type : 4; + u64 reserved0 : 28; + u64 req_sept_level : 3; + u64 err_sept_level : 3; + u64 err_sept_state : 8; + u64 err_sept_is_leaf : 1; + u64 reserved1 : 17; + }; + u64 full; +}; + +enum tdx_ext_exit_qualification_type { + EXT_EXIT_QUAL_NONE, + EXT_EXIT_QUAL_ACCEPT, + NUM_EXT_EXIT_QUAL, +}; + struct vcpu_tdx { struct kvm_vcpu vcpu; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 28732925792e..ae9ba0731521 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -5753,7 +5753,7 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu) if (unlikely(allow_smaller_maxphyaddr && kvm_vcpu_is_illegal_gpa(vcpu, gpa))) return kvm_emulate_instruction(vcpu, 0); - return __vmx_handle_ept_violation(vcpu, gpa, exit_qualification); + return __vmx_handle_ept_violation(vcpu, gpa, exit_qualification, 0); } static int handle_ept_misconfig(struct kvm_vcpu *vcpu)