From 37a41847b770c722e98ace72f3851fb49b360c08 Mon Sep 17 00:00:00 2001 From: Binbin Wu Date: Wed, 13 Sep 2023 20:42:19 +0800 Subject: KVM: x86: Introduce get_untagged_addr() in kvm_x86_ops and call it in emulator Introduce a new interface get_untagged_addr() to kvm_x86_ops to untag the metadata from linear address. Call the interface in linearization of instruction emulator for 64-bit mode. When enabled feature like Intel Linear Address Masking (LAM) or AMD Upper Address Ignore (UAI), linear addresses may be tagged with metadata that needs to be dropped prior to canonicality checks, i.e. the metadata is ignored. Introduce get_untagged_addr() to kvm_x86_ops to hide the vendor specific code, as sadly LAM and UAI have different semantics. Pass the emulator flags to allow vendor specific implementation to precisely identify the access type (LAM doesn't untag certain accesses). Signed-off-by: Binbin Wu Reviewed-by: Chao Gao Tested-by: Xuelian Guo Link: https://lore.kernel.org/r/20230913124227.12574-9-binbin.wu@linux.intel.com [sean: massage changelog] Signed-off-by: Sean Christopherson --- arch/x86/include/asm/kvm-x86-ops.h | 1 + arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/emulate.c | 2 +- arch/x86/kvm/kvm_emulate.h | 3 +++ arch/x86/kvm/x86.c | 10 ++++++++++ 5 files changed, 17 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 26b628d84594..756791665117 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -135,6 +135,7 @@ KVM_X86_OP(msr_filter_changed) KVM_X86_OP(complete_emulated_msr) KVM_X86_OP(vcpu_deliver_sipi_vector) KVM_X86_OP_OPTIONAL_RET0(vcpu_get_apicv_inhibit_reasons); +KVM_X86_OP_OPTIONAL(get_untagged_addr) #undef KVM_X86_OP #undef KVM_X86_OP_OPTIONAL diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a565a2e70f30..8d042f27d644 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1762,6 +1762,8 @@ struct kvm_x86_ops { * Returns vCPU specific APICv inhibit reasons */ unsigned long (*vcpu_get_apicv_inhibit_reasons)(struct kvm_vcpu *vcpu); + + gva_t (*get_untagged_addr)(struct kvm_vcpu *vcpu, gva_t gva, unsigned int flags); }; struct kvm_x86_nested_ops { diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index ceec8c5f9687..e223043ef5b2 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -701,7 +701,7 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt, *max_size = 0; switch (mode) { case X86EMUL_MODE_PROT64: - *linear = la; + *linear = la = ctxt->ops->get_untagged_addr(ctxt, la, flags); va_bits = ctxt_virt_addr_bits(ctxt); if (!__is_canonical_address(la, va_bits)) goto bad; diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h index 8bd9b23543cc..e6d149825169 100644 --- a/arch/x86/kvm/kvm_emulate.h +++ b/arch/x86/kvm/kvm_emulate.h @@ -230,6 +230,9 @@ struct x86_emulate_ops { int (*leave_smm)(struct x86_emulate_ctxt *ctxt); void (*triple_fault)(struct x86_emulate_ctxt *ctxt); int (*set_xcr)(struct x86_emulate_ctxt *ctxt, u32 index, u64 xcr); + + gva_t (*get_untagged_addr)(struct x86_emulate_ctxt *ctxt, gva_t addr, + unsigned int flags); }; /* Type, address-of, and value of an instruction's operand. */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3a648b6e632d..557872c0331a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8445,6 +8445,15 @@ static void emulator_vm_bugged(struct x86_emulate_ctxt *ctxt) kvm_vm_bugged(kvm); } +static gva_t emulator_get_untagged_addr(struct x86_emulate_ctxt *ctxt, + gva_t addr, unsigned int flags) +{ + if (!kvm_x86_ops.get_untagged_addr) + return addr; + + return static_call(kvm_x86_get_untagged_addr)(emul_to_vcpu(ctxt), addr, flags); +} + static const struct x86_emulate_ops emulate_ops = { .vm_bugged = emulator_vm_bugged, .read_gpr = emulator_read_gpr, @@ -8489,6 +8498,7 @@ static const struct x86_emulate_ops emulate_ops = { .leave_smm = emulator_leave_smm, .triple_fault = emulator_triple_fault, .set_xcr = emulator_set_xcr, + .get_untagged_addr = emulator_get_untagged_addr, }; static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask) -- cgit