| Message ID | 20230601142309.6307-5-guang.zeng@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | LASS KVM virtualization support | expand |
On Thu, Jun 01, 2023, Zeng Guang wrote: > When LASS is enabled, KVM need apply LASS violation check to instruction > emulations. Add helper for the usage of x86 emulator to perform LASS > protection. > > Signed-off-by: Zeng Guang <guang.zeng@intel.com> > Tested-by: Xuelian Guo <xuelian.guo@intel.com> > --- > arch/x86/kvm/kvm_emulate.h | 1 + > arch/x86/kvm/x86.c | 12 ++++++++++++ > 2 files changed, 13 insertions(+) > > diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h > index f1439ab7c14b..fd1c2b22867e 100644 > --- a/arch/x86/kvm/kvm_emulate.h > +++ b/arch/x86/kvm/kvm_emulate.h > @@ -230,6 +230,7 @@ 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); > + bool (*check_lass)(struct x86_emulate_ctxt *ctxt, u64 access, u64 la, u32 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 c0778ca39650..faf01fecc4ca 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -8287,6 +8287,17 @@ static void emulator_vm_bugged(struct x86_emulate_ctxt *ctxt) > kvm_vm_bugged(kvm); > } > > +static bool emulator_check_lass(struct x86_emulate_ctxt *ctxt, > + u64 access, u64 la, u32 flags) > +{ > + struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt); > + > + if (!is_long_mode(vcpu)) > + return false; Likely a moot point if we wrap ->gva_to_gpa(), but most this into the vendor implementation. And if we keep these emulator hooks, massage the patch ordering: 1. Add plumbing to emulator to pass new flags 2. Add kvm_x86_ops definition and invocation from emulator 3. Implement and wire up vmx_is_lass_violation() That way the changes to each area of KVM are better isolated. > + return static_call(kvm_x86_check_lass)(vcpu, access, la, flags); > +} > + > static const struct x86_emulate_ops emulate_ops = { > .vm_bugged = emulator_vm_bugged, > .read_gpr = emulator_read_gpr, > @@ -8332,6 +8343,7 @@ static const struct x86_emulate_ops emulate_ops = { > .leave_smm = emulator_leave_smm, > .triple_fault = emulator_triple_fault, > .set_xcr = emulator_set_xcr, > + .check_lass = emulator_check_lass, > }; > > static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask) > -- > 2.27.0 >
On 6/28/2023 2:28 AM, Sean Christopherson wrote: > On Thu, Jun 01, 2023, Zeng Guang wrote: >> When LASS is enabled, KVM need apply LASS violation check to instruction >> emulations. Add helper for the usage of x86 emulator to perform LASS >> protection. >> >> Signed-off-by: Zeng Guang <guang.zeng@intel.com> >> Tested-by: Xuelian Guo <xuelian.guo@intel.com> >> --- >> arch/x86/kvm/kvm_emulate.h | 1 + >> arch/x86/kvm/x86.c | 12 ++++++++++++ >> 2 files changed, 13 insertions(+) >> >> diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h >> index f1439ab7c14b..fd1c2b22867e 100644 >> --- a/arch/x86/kvm/kvm_emulate.h >> +++ b/arch/x86/kvm/kvm_emulate.h >> @@ -230,6 +230,7 @@ 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); >> + bool (*check_lass)(struct x86_emulate_ctxt *ctxt, u64 access, u64 la, u32 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 c0778ca39650..faf01fecc4ca 100644 >> --- a/arch/x86/kvm/x86.c >> +++ b/arch/x86/kvm/x86.c >> @@ -8287,6 +8287,17 @@ static void emulator_vm_bugged(struct x86_emulate_ctxt *ctxt) >> kvm_vm_bugged(kvm); >> } >> >> +static bool emulator_check_lass(struct x86_emulate_ctxt *ctxt, >> + u64 access, u64 la, u32 flags) >> +{ >> + struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt); >> + >> + if (!is_long_mode(vcpu)) >> + return false; > Likely a moot point if we wrap ->gva_to_gpa(), but most this into the vendor > implementation. It's right way to move cpu mode check into is_lass_violation(). Previously I was struggling to expect getting benefit from separate invocation. But it doesn't help much indeed. > > And if we keep these emulator hooks, massage the patch ordering: > > 1. Add plumbing to emulator to pass new flags > 2. Add kvm_x86_ops definition and invocation from emulator > 3. Implement and wire up vmx_is_lass_violation() > > That way the changes to each area of KVM are better isolated. OK. Will reorganize the patch accordingly. Thanks. >> + return static_call(kvm_x86_check_lass)(vcpu, access, la, flags); >> +} >> + >> static const struct x86_emulate_ops emulate_ops = { >> .vm_bugged = emulator_vm_bugged, >> .read_gpr = emulator_read_gpr, >> @@ -8332,6 +8343,7 @@ static const struct x86_emulate_ops emulate_ops = { >> .leave_smm = emulator_leave_smm, >> .triple_fault = emulator_triple_fault, >> .set_xcr = emulator_set_xcr, >> + .check_lass = emulator_check_lass, >> }; >> >> static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask) >> -- >> 2.27.0 >>
diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h index f1439ab7c14b..fd1c2b22867e 100644 --- a/arch/x86/kvm/kvm_emulate.h +++ b/arch/x86/kvm/kvm_emulate.h @@ -230,6 +230,7 @@ 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); + bool (*check_lass)(struct x86_emulate_ctxt *ctxt, u64 access, u64 la, u32 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 c0778ca39650..faf01fecc4ca 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8287,6 +8287,17 @@ static void emulator_vm_bugged(struct x86_emulate_ctxt *ctxt) kvm_vm_bugged(kvm); } +static bool emulator_check_lass(struct x86_emulate_ctxt *ctxt, + u64 access, u64 la, u32 flags) +{ + struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt); + + if (!is_long_mode(vcpu)) + return false; + + return static_call(kvm_x86_check_lass)(vcpu, access, la, flags); +} + static const struct x86_emulate_ops emulate_ops = { .vm_bugged = emulator_vm_bugged, .read_gpr = emulator_read_gpr, @@ -8332,6 +8343,7 @@ static const struct x86_emulate_ops emulate_ops = { .leave_smm = emulator_leave_smm, .triple_fault = emulator_triple_fault, .set_xcr = emulator_set_xcr, + .check_lass = emulator_check_lass, }; static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask)