* [PATCH 0/2] KVM: arm64: Minor pKVM cleanups
@ 2022-05-09 16:25 Oliver Upton
2022-05-09 16:25 ` [PATCH 1/2] KVM: arm64: pkvm: Drop unnecessary FP/SIMD trap handler Oliver Upton
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Oliver Upton @ 2022-05-09 16:25 UTC (permalink / raw)
To: kvmarm
Cc: kvm, linux-arm-kernel, linux-kernel, maz, james.morse,
alexandru.elisei, suzuki.poulose, tabba, qperret, will,
Oliver Upton
I was reading through some of the pKVM stuff to get an idea of how it
handles feature registers and spotted a few minor nits.
Applies cleanly to 5.18-rc5.
Oliver Upton (2):
KVM: arm64: pkvm: Drop unnecessary FP/SIMD trap handler
KVM: arm64: pkvm: Don't mask already zeroed FEAT_SVE
arch/arm64/kvm/hyp/nvhe/switch.c | 19 +------------------
arch/arm64/kvm/hyp/nvhe/sys_regs.c | 3 ---
2 files changed, 1 insertion(+), 21 deletions(-)
--
2.36.0.512.ge40c2bad7a-goog
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH 1/2] KVM: arm64: pkvm: Drop unnecessary FP/SIMD trap handler 2022-05-09 16:25 [PATCH 0/2] KVM: arm64: Minor pKVM cleanups Oliver Upton @ 2022-05-09 16:25 ` Oliver Upton 2022-05-10 9:44 ` Fuad Tabba 2022-05-09 16:25 ` [PATCH 2/2] KVM: arm64: pkvm: Don't mask already zeroed FEAT_SVE Oliver Upton 2022-05-10 10:04 ` [PATCH 0/2] KVM: arm64: Minor pKVM cleanups Marc Zyngier 2 siblings, 1 reply; 6+ messages in thread From: Oliver Upton @ 2022-05-09 16:25 UTC (permalink / raw) To: kvmarm Cc: kvm, linux-arm-kernel, linux-kernel, maz, james.morse, alexandru.elisei, suzuki.poulose, tabba, qperret, will, Oliver Upton The pVM-specific FP/SIMD trap handler just calls straight into the generic trap handler. Avoid the indirection and just call the hyp handler directly. Note that the BUILD_BUG_ON() pattern is repeated in pvm_init_traps_aa64pfr0(), which is likely a better home for it. No functional change intended. Signed-off-by: Oliver Upton <oupton@google.com> --- arch/arm64/kvm/hyp/nvhe/switch.c | 19 +------------------ 1 file changed, 1 insertion(+), 18 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index 6410d21d8695..3dee2ad96e10 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -175,23 +175,6 @@ static bool kvm_handle_pvm_sys64(struct kvm_vcpu *vcpu, u64 *exit_code) kvm_handle_pvm_sysreg(vcpu, exit_code)); } -/** - * Handler for protected floating-point and Advanced SIMD accesses. - * - * Returns true if the hypervisor has handled the exit, and control should go - * back to the guest, or false if it hasn't. - */ -static bool kvm_handle_pvm_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) -{ - /* Linux guests assume support for floating-point and Advanced SIMD. */ - BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_FP), - PVM_ID_AA64PFR0_ALLOW)); - BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_ASIMD), - PVM_ID_AA64PFR0_ALLOW)); - - return kvm_hyp_handle_fpsimd(vcpu, exit_code); -} - static const exit_handler_fn hyp_exit_handlers[] = { [0 ... ESR_ELx_EC_MAX] = NULL, [ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32, @@ -207,7 +190,7 @@ static const exit_handler_fn pvm_exit_handlers[] = { [0 ... ESR_ELx_EC_MAX] = NULL, [ESR_ELx_EC_SYS64] = kvm_handle_pvm_sys64, [ESR_ELx_EC_SVE] = kvm_handle_pvm_restricted, - [ESR_ELx_EC_FP_ASIMD] = kvm_handle_pvm_fpsimd, + [ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd, [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, -- 2.36.0.512.ge40c2bad7a-goog ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] KVM: arm64: pkvm: Drop unnecessary FP/SIMD trap handler 2022-05-09 16:25 ` [PATCH 1/2] KVM: arm64: pkvm: Drop unnecessary FP/SIMD trap handler Oliver Upton @ 2022-05-10 9:44 ` Fuad Tabba 0 siblings, 0 replies; 6+ messages in thread From: Fuad Tabba @ 2022-05-10 9:44 UTC (permalink / raw) To: Oliver Upton Cc: kvmarm, kvm, linux-arm-kernel, linux-kernel, maz, james.morse, alexandru.elisei, suzuki.poulose, qperret, will Hi Oliver, On Mon, May 9, 2022 at 5:26 PM Oliver Upton <oupton@google.com> wrote: > > The pVM-specific FP/SIMD trap handler just calls straight into the > generic trap handler. Avoid the indirection and just call the hyp > handler directly. > > Note that the BUILD_BUG_ON() pattern is repeated in > pvm_init_traps_aa64pfr0(), which is likely a better home for it. > > No functional change intended. Reviewed-by: Fuad Tabba <tabba@google.com> Cheers, /fuad > > Signed-off-by: Oliver Upton <oupton@google.com> > --- > arch/arm64/kvm/hyp/nvhe/switch.c | 19 +------------------ > 1 file changed, 1 insertion(+), 18 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c > index 6410d21d8695..3dee2ad96e10 100644 > --- a/arch/arm64/kvm/hyp/nvhe/switch.c > +++ b/arch/arm64/kvm/hyp/nvhe/switch.c > @@ -175,23 +175,6 @@ static bool kvm_handle_pvm_sys64(struct kvm_vcpu *vcpu, u64 *exit_code) > kvm_handle_pvm_sysreg(vcpu, exit_code)); > } > > -/** > - * Handler for protected floating-point and Advanced SIMD accesses. > - * > - * Returns true if the hypervisor has handled the exit, and control should go > - * back to the guest, or false if it hasn't. > - */ > -static bool kvm_handle_pvm_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) > -{ > - /* Linux guests assume support for floating-point and Advanced SIMD. */ > - BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_FP), > - PVM_ID_AA64PFR0_ALLOW)); > - BUILD_BUG_ON(!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_ASIMD), > - PVM_ID_AA64PFR0_ALLOW)); > - > - return kvm_hyp_handle_fpsimd(vcpu, exit_code); > -} > - > static const exit_handler_fn hyp_exit_handlers[] = { > [0 ... ESR_ELx_EC_MAX] = NULL, > [ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32, > @@ -207,7 +190,7 @@ static const exit_handler_fn pvm_exit_handlers[] = { > [0 ... ESR_ELx_EC_MAX] = NULL, > [ESR_ELx_EC_SYS64] = kvm_handle_pvm_sys64, > [ESR_ELx_EC_SVE] = kvm_handle_pvm_restricted, > - [ESR_ELx_EC_FP_ASIMD] = kvm_handle_pvm_fpsimd, > + [ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd, > [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, > [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, > [ESR_ELx_EC_PAC] = kvm_hyp_handle_ptrauth, > -- > 2.36.0.512.ge40c2bad7a-goog > ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 2/2] KVM: arm64: pkvm: Don't mask already zeroed FEAT_SVE 2022-05-09 16:25 [PATCH 0/2] KVM: arm64: Minor pKVM cleanups Oliver Upton 2022-05-09 16:25 ` [PATCH 1/2] KVM: arm64: pkvm: Drop unnecessary FP/SIMD trap handler Oliver Upton @ 2022-05-09 16:25 ` Oliver Upton 2022-05-10 9:45 ` Fuad Tabba 2022-05-10 10:04 ` [PATCH 0/2] KVM: arm64: Minor pKVM cleanups Marc Zyngier 2 siblings, 1 reply; 6+ messages in thread From: Oliver Upton @ 2022-05-09 16:25 UTC (permalink / raw) To: kvmarm Cc: kvm, linux-arm-kernel, linux-kernel, maz, james.morse, alexandru.elisei, suzuki.poulose, tabba, qperret, will, Oliver Upton FEAT_SVE is already masked by the fixed configuration for ID_AA64PFR0_EL1; don't try and mask it at runtime. No functional change intended. Signed-off-by: Oliver Upton <oupton@google.com> --- arch/arm64/kvm/hyp/nvhe/sys_regs.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c index 33f5181af330..3f5d7bd171c5 100644 --- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c @@ -90,9 +90,6 @@ static u64 get_pvm_id_aa64pfr0(const struct kvm_vcpu *vcpu) u64 set_mask = 0; u64 allow_mask = PVM_ID_AA64PFR0_ALLOW; - if (!vcpu_has_sve(vcpu)) - allow_mask &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_SVE); - set_mask |= get_restricted_features_unsigned(id_aa64pfr0_el1_sys_val, PVM_ID_AA64PFR0_RESTRICT_UNSIGNED); -- 2.36.0.512.ge40c2bad7a-goog ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] KVM: arm64: pkvm: Don't mask already zeroed FEAT_SVE 2022-05-09 16:25 ` [PATCH 2/2] KVM: arm64: pkvm: Don't mask already zeroed FEAT_SVE Oliver Upton @ 2022-05-10 9:45 ` Fuad Tabba 0 siblings, 0 replies; 6+ messages in thread From: Fuad Tabba @ 2022-05-10 9:45 UTC (permalink / raw) To: Oliver Upton Cc: kvmarm, kvm, linux-arm-kernel, linux-kernel, maz, james.morse, alexandru.elisei, suzuki.poulose, qperret, will Hi Oliver, On Mon, May 9, 2022 at 5:26 PM Oliver Upton <oupton@google.com> wrote: > > FEAT_SVE is already masked by the fixed configuration for > ID_AA64PFR0_EL1; don't try and mask it at runtime. > > No functional change intended. > > Signed-off-by: Oliver Upton <oupton@google.com> > --- Reviewed-by: Fuad Tabba <tabba@google.com> Cheers, /fuad > arch/arm64/kvm/hyp/nvhe/sys_regs.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c > index 33f5181af330..3f5d7bd171c5 100644 > --- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c > +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c > @@ -90,9 +90,6 @@ static u64 get_pvm_id_aa64pfr0(const struct kvm_vcpu *vcpu) > u64 set_mask = 0; > u64 allow_mask = PVM_ID_AA64PFR0_ALLOW; > > - if (!vcpu_has_sve(vcpu)) > - allow_mask &= ~ARM64_FEATURE_MASK(ID_AA64PFR0_SVE); > - > set_mask |= get_restricted_features_unsigned(id_aa64pfr0_el1_sys_val, > PVM_ID_AA64PFR0_RESTRICT_UNSIGNED); > > -- > 2.36.0.512.ge40c2bad7a-goog > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 0/2] KVM: arm64: Minor pKVM cleanups 2022-05-09 16:25 [PATCH 0/2] KVM: arm64: Minor pKVM cleanups Oliver Upton 2022-05-09 16:25 ` [PATCH 1/2] KVM: arm64: pkvm: Drop unnecessary FP/SIMD trap handler Oliver Upton 2022-05-09 16:25 ` [PATCH 2/2] KVM: arm64: pkvm: Don't mask already zeroed FEAT_SVE Oliver Upton @ 2022-05-10 10:04 ` Marc Zyngier 2 siblings, 0 replies; 6+ messages in thread From: Marc Zyngier @ 2022-05-10 10:04 UTC (permalink / raw) To: kvmarm, Oliver Upton Cc: will, tabba, qperret, james.morse, alexandru.elisei, kvm, suzuki.poulose, linux-arm-kernel, linux-kernel On Mon, 9 May 2022 16:25:57 +0000, Oliver Upton wrote: > I was reading through some of the pKVM stuff to get an idea of how it > handles feature registers and spotted a few minor nits. > > Applies cleanly to 5.18-rc5. > > Oliver Upton (2): > KVM: arm64: pkvm: Drop unnecessary FP/SIMD trap handler > KVM: arm64: pkvm: Don't mask already zeroed FEAT_SVE > > [...] Applied to next, thanks! [1/2] KVM: arm64: pkvm: Drop unnecessary FP/SIMD trap handler commit: 4d2e469e163ec79340b2f42c2a07838b5ff30686 [2/2] KVM: arm64: pkvm: Don't mask already zeroed FEAT_SVE commit: 249838b7660ac04a67bfb017364a7f01029370a0 Cheers, M. -- Without deviation from the norm, progress is not possible. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-05-10 10:05 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-05-09 16:25 [PATCH 0/2] KVM: arm64: Minor pKVM cleanups Oliver Upton 2022-05-09 16:25 ` [PATCH 1/2] KVM: arm64: pkvm: Drop unnecessary FP/SIMD trap handler Oliver Upton 2022-05-10 9:44 ` Fuad Tabba 2022-05-09 16:25 ` [PATCH 2/2] KVM: arm64: pkvm: Don't mask already zeroed FEAT_SVE Oliver Upton 2022-05-10 9:45 ` Fuad Tabba 2022-05-10 10:04 ` [PATCH 0/2] KVM: arm64: Minor pKVM cleanups Marc Zyngier
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