| Message ID | 20240503130147.1154804-10-joey.gouly@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Permission Overlay Extension | expand |
On Fri, 03 May 2024 14:01:27 +0100, Joey Gouly <joey.gouly@arm.com> wrote: > > FEAT_ATS1E1A introduces a new instruction: `at s1e1a`. > This is an address translation, without permission checks. > > POE allows read permissions to be removed from S1 by the guest. This means > that an `at` instruction could fail, and not get the IPA. > > Switch to using `at s1e1a` so that KVM can get the IPA regardless of S1 > permissions. > > Signed-off-by: Joey Gouly <joey.gouly@arm.com> > Cc: Marc Zyngier <maz@kernel.org> > Cc: Oliver Upton <oliver.upton@linux.dev> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > --- > arch/arm64/kvm/hyp/include/hyp/fault.h | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/hyp/include/hyp/fault.h b/arch/arm64/kvm/hyp/include/hyp/fault.h > index 487c06099d6f..17df94570f03 100644 > --- a/arch/arm64/kvm/hyp/include/hyp/fault.h > +++ b/arch/arm64/kvm/hyp/include/hyp/fault.h > @@ -14,6 +14,7 @@ > > static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar) > { > + int ret; > u64 par, tmp; > > /* > @@ -27,7 +28,9 @@ static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar) > * saved the guest context yet, and we may return early... > */ > par = read_sysreg_par(); > - if (!__kvm_at(OP_AT_S1E1R, far)) > + ret = system_supports_poe() ? __kvm_at(OP_AT_S1E1A, far) : > + __kvm_at(OP_AT_S1E1R, far); > + if (!ret) > tmp = read_sysreg_par(); > else > tmp = SYS_PAR_EL1_F; /* back to the guest */ Reviewed-by: Marc Zyngier <maz@kernel.org> M.
On 5/3/24 18:31, Joey Gouly wrote: > FEAT_ATS1E1A introduces a new instruction: `at s1e1a`. > This is an address translation, without permission checks. > > POE allows read permissions to be removed from S1 by the guest. This means > that an `at` instruction could fail, and not get the IPA. > > Switch to using `at s1e1a` so that KVM can get the IPA regardless of S1 > permissions. > > Signed-off-by: Joey Gouly <joey.gouly@arm.com> > Cc: Marc Zyngier <maz@kernel.org> > Cc: Oliver Upton <oliver.upton@linux.dev> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > --- > arch/arm64/kvm/hyp/include/hyp/fault.h | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/hyp/include/hyp/fault.h b/arch/arm64/kvm/hyp/include/hyp/fault.h > index 487c06099d6f..17df94570f03 100644 > --- a/arch/arm64/kvm/hyp/include/hyp/fault.h > +++ b/arch/arm64/kvm/hyp/include/hyp/fault.h > @@ -14,6 +14,7 @@ > > static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar) > { > + int ret; > u64 par, tmp; > > /* > @@ -27,7 +28,9 @@ static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar) > * saved the guest context yet, and we may return early... > */ > par = read_sysreg_par(); > - if (!__kvm_at(OP_AT_S1E1R, far)) > + ret = system_supports_poe() ? __kvm_at(OP_AT_S1E1A, far) : > + __kvm_at(OP_AT_S1E1R, far); > + if (!ret) > tmp = read_sysreg_par(); > else > tmp = SYS_PAR_EL1_F; /* back to the guest */ Since the idea is to get the IPA, using OP_AT_S1E1A instead, makes sense when POE is enabled. Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
diff --git a/arch/arm64/kvm/hyp/include/hyp/fault.h b/arch/arm64/kvm/hyp/include/hyp/fault.h index 487c06099d6f..17df94570f03 100644 --- a/arch/arm64/kvm/hyp/include/hyp/fault.h +++ b/arch/arm64/kvm/hyp/include/hyp/fault.h @@ -14,6 +14,7 @@ static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar) { + int ret; u64 par, tmp; /* @@ -27,7 +28,9 @@ static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar) * saved the guest context yet, and we may return early... */ par = read_sysreg_par(); - if (!__kvm_at(OP_AT_S1E1R, far)) + ret = system_supports_poe() ? __kvm_at(OP_AT_S1E1A, far) : + __kvm_at(OP_AT_S1E1R, far); + if (!ret) tmp = read_sysreg_par(); else tmp = SYS_PAR_EL1_F; /* back to the guest */
FEAT_ATS1E1A introduces a new instruction: `at s1e1a`. This is an address translation, without permission checks. POE allows read permissions to be removed from S1 by the guest. This means that an `at` instruction could fail, and not get the IPA. Switch to using `at s1e1a` so that KVM can get the IPA regardless of S1 permissions. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> --- arch/arm64/kvm/hyp/include/hyp/fault.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)