| Message ID | 20210923191610.3814698-4-oupton@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Implement PSCI SYSTEM_SUSPEND support | expand |
On Thu, Sep 23, 2021 at 12:16 PM Oliver Upton <oupton@google.com> wrote: > > In its implementation of the PSCI function, KVM needs to request that a > target vCPU resets before its next entry into the guest. Wrap the logic > for requesting a reset in a function for later use by other implemented > PSCI calls. > > No functional change intended. > > Signed-off-by: Oliver Upton <oupton@google.com> > --- > arch/arm64/kvm/psci.c | 59 +++++++++++++++++++++++++------------------ > 1 file changed, 35 insertions(+), 24 deletions(-) > > diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c > index 310b9cb2b32b..bb59b692998b 100644 > --- a/arch/arm64/kvm/psci.c > +++ b/arch/arm64/kvm/psci.c > @@ -64,9 +64,40 @@ static inline bool kvm_psci_valid_affinity(unsigned long affinity) > return !(affinity & ~MPIDR_HWID_BITMASK); > } > > -static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > +static void kvm_psci_vcpu_request_reset(struct kvm_vcpu *vcpu, > + unsigned long entry_addr, > + unsigned long context_id, > + bool big_endian) > { > struct vcpu_reset_state *reset_state; > + > + lockdep_assert_held(&vcpu->kvm->lock); > + > + reset_state = &vcpu->arch.reset_state; > + reset_state->pc = entry_addr; > + > + /* Propagate caller endianness */ > + reset_state->be = big_endian; > + > + /* > + * NOTE: We always update r0 (or x0) because for PSCI v0.1 > + * the general purpose registers are undefined upon CPU_ON. > + */ > + reset_state->r0 = context_id; > + > + WRITE_ONCE(reset_state->reset, true); > + kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > + > + /* > + * Make sure the reset request is observed if the change to > + * power_state is observed. > + */ > + smp_wmb(); > + vcpu->arch.power_off = false; > +} > + > +static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > +{ > struct kvm *kvm = source_vcpu->kvm; > struct kvm_vcpu *vcpu = NULL; > unsigned long cpu_id; > @@ -90,29 +121,9 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > return PSCI_RET_INVALID_PARAMS; > } > > - reset_state = &vcpu->arch.reset_state; > - > - reset_state->pc = smccc_get_arg2(source_vcpu); > - > - /* Propagate caller endianness */ > - reset_state->be = kvm_vcpu_is_be(source_vcpu); > - > - /* > - * NOTE: We always update r0 (or x0) because for PSCI v0.1 > - * the general purpose registers are undefined upon CPU_ON. > - */ > - reset_state->r0 = smccc_get_arg3(source_vcpu); > - > - WRITE_ONCE(reset_state->reset, true); > - kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > - > - /* > - * Make sure the reset request is observed if the change to > - * power_state is observed. > - */ > - smp_wmb(); > - > - vcpu->arch.power_off = false; > + kvm_psci_vcpu_request_reset(vcpu, smccc_get_arg2(source_vcpu), > + smccc_get_arg3(source_vcpu), > + kvm_vcpu_is_be(source_vcpu)); > kvm_vcpu_wake_up(vcpu); > > return PSCI_RET_SUCCESS; > -- > 2.33.0.685.g46640cef36-goog Reviewed-by: Reiji Watanabe <reijiw@google.com> Not directly related to the patch, but the (original) code doesn't do any sanity checking for the entry address although the PSCI spec says: "INVALID_ADDRESS is returned when the entry point address is known by the implementation to be invalid, because it is in a range that is known not to be available to the caller." Thanks, Reiji
On Thu, Sep 30, 2021 at 11:05 PM Reiji Watanabe <reijiw@google.com> wrote: > > On Thu, Sep 23, 2021 at 12:16 PM Oliver Upton <oupton@google.com> wrote: > > > > In its implementation of the PSCI function, KVM needs to request that a > > target vCPU resets before its next entry into the guest. Wrap the logic > > for requesting a reset in a function for later use by other implemented > > PSCI calls. > > > > No functional change intended. > > > > Signed-off-by: Oliver Upton <oupton@google.com> > > --- > > arch/arm64/kvm/psci.c | 59 +++++++++++++++++++++++++------------------ > > 1 file changed, 35 insertions(+), 24 deletions(-) > > > > diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c > > index 310b9cb2b32b..bb59b692998b 100644 > > --- a/arch/arm64/kvm/psci.c > > +++ b/arch/arm64/kvm/psci.c > > @@ -64,9 +64,40 @@ static inline bool kvm_psci_valid_affinity(unsigned long affinity) > > return !(affinity & ~MPIDR_HWID_BITMASK); > > } > > > > -static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > +static void kvm_psci_vcpu_request_reset(struct kvm_vcpu *vcpu, > > + unsigned long entry_addr, > > + unsigned long context_id, > > + bool big_endian) > > { > > struct vcpu_reset_state *reset_state; > > + > > + lockdep_assert_held(&vcpu->kvm->lock); > > + > > + reset_state = &vcpu->arch.reset_state; > > + reset_state->pc = entry_addr; > > + > > + /* Propagate caller endianness */ > > + reset_state->be = big_endian; > > + > > + /* > > + * NOTE: We always update r0 (or x0) because for PSCI v0.1 > > + * the general purpose registers are undefined upon CPU_ON. > > + */ > > + reset_state->r0 = context_id; > > + > > + WRITE_ONCE(reset_state->reset, true); > > + kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > > + > > + /* > > + * Make sure the reset request is observed if the change to > > + * power_state is observed. > > + */ > > + smp_wmb(); > > + vcpu->arch.power_off = false; > > +} > > + > > +static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > +{ > > struct kvm *kvm = source_vcpu->kvm; > > struct kvm_vcpu *vcpu = NULL; > > unsigned long cpu_id; > > @@ -90,29 +121,9 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > return PSCI_RET_INVALID_PARAMS; > > } > > > > - reset_state = &vcpu->arch.reset_state; > > - > > - reset_state->pc = smccc_get_arg2(source_vcpu); > > - > > - /* Propagate caller endianness */ > > - reset_state->be = kvm_vcpu_is_be(source_vcpu); > > - > > - /* > > - * NOTE: We always update r0 (or x0) because for PSCI v0.1 > > - * the general purpose registers are undefined upon CPU_ON. > > - */ > > - reset_state->r0 = smccc_get_arg3(source_vcpu); > > - > > - WRITE_ONCE(reset_state->reset, true); > > - kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > > - > > - /* > > - * Make sure the reset request is observed if the change to > > - * power_state is observed. > > - */ > > - smp_wmb(); > > - > > - vcpu->arch.power_off = false; > > + kvm_psci_vcpu_request_reset(vcpu, smccc_get_arg2(source_vcpu), > > + smccc_get_arg3(source_vcpu), > > + kvm_vcpu_is_be(source_vcpu)); > > kvm_vcpu_wake_up(vcpu); > > > > return PSCI_RET_SUCCESS; > > -- > > 2.33.0.685.g46640cef36-goog > > Reviewed-by: Reiji Watanabe <reijiw@google.com> > > Not directly related to the patch, but the (original) code doesn't > do any sanity checking for the entry address although the PSCI spec says: > > "INVALID_ADDRESS is returned when the entry point address is known > by the implementation to be invalid, because it is in a range that > is known not to be available to the caller." Right, I had noticed the same but was a tad too lazy to address in this series :) Thanks for the review, Reji! -- Best, Oliver
On Fri, Oct 01, 2021 at 09:10:14AM -0700, Oliver Upton wrote: > On Thu, Sep 30, 2021 at 11:05 PM Reiji Watanabe <reijiw@google.com> wrote: > > > > On Thu, Sep 23, 2021 at 12:16 PM Oliver Upton <oupton@google.com> wrote: > > > > > > In its implementation of the PSCI function, KVM needs to request that a > > > target vCPU resets before its next entry into the guest. Wrap the logic > > > for requesting a reset in a function for later use by other implemented > > > PSCI calls. > > > > > > No functional change intended. > > > > > > Signed-off-by: Oliver Upton <oupton@google.com> > > > --- > > > arch/arm64/kvm/psci.c | 59 +++++++++++++++++++++++++------------------ > > > 1 file changed, 35 insertions(+), 24 deletions(-) > > > > > > diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c > > > index 310b9cb2b32b..bb59b692998b 100644 > > > --- a/arch/arm64/kvm/psci.c > > > +++ b/arch/arm64/kvm/psci.c > > > @@ -64,9 +64,40 @@ static inline bool kvm_psci_valid_affinity(unsigned long affinity) > > > return !(affinity & ~MPIDR_HWID_BITMASK); > > > } > > > > > > -static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > > +static void kvm_psci_vcpu_request_reset(struct kvm_vcpu *vcpu, > > > + unsigned long entry_addr, > > > + unsigned long context_id, > > > + bool big_endian) > > > { > > > struct vcpu_reset_state *reset_state; > > > + > > > + lockdep_assert_held(&vcpu->kvm->lock); > > > + > > > + reset_state = &vcpu->arch.reset_state; > > > + reset_state->pc = entry_addr; > > > + > > > + /* Propagate caller endianness */ > > > + reset_state->be = big_endian; > > > + > > > + /* > > > + * NOTE: We always update r0 (or x0) because for PSCI v0.1 > > > + * the general purpose registers are undefined upon CPU_ON. > > > + */ > > > + reset_state->r0 = context_id; > > > + > > > + WRITE_ONCE(reset_state->reset, true); > > > + kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > > > + > > > + /* > > > + * Make sure the reset request is observed if the change to > > > + * power_state is observed. > > > + */ > > > + smp_wmb(); > > > + vcpu->arch.power_off = false; > > > +} > > > + > > > +static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > > +{ > > > struct kvm *kvm = source_vcpu->kvm; > > > struct kvm_vcpu *vcpu = NULL; > > > unsigned long cpu_id; > > > @@ -90,29 +121,9 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > > return PSCI_RET_INVALID_PARAMS; > > > } > > > > > > - reset_state = &vcpu->arch.reset_state; > > > - > > > - reset_state->pc = smccc_get_arg2(source_vcpu); > > > - > > > - /* Propagate caller endianness */ > > > - reset_state->be = kvm_vcpu_is_be(source_vcpu); > > > - > > > - /* > > > - * NOTE: We always update r0 (or x0) because for PSCI v0.1 > > > - * the general purpose registers are undefined upon CPU_ON. > > > - */ > > > - reset_state->r0 = smccc_get_arg3(source_vcpu); > > > - > > > - WRITE_ONCE(reset_state->reset, true); > > > - kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > > > - > > > - /* > > > - * Make sure the reset request is observed if the change to > > > - * power_state is observed. > > > - */ > > > - smp_wmb(); > > > - > > > - vcpu->arch.power_off = false; > > > + kvm_psci_vcpu_request_reset(vcpu, smccc_get_arg2(source_vcpu), > > > + smccc_get_arg3(source_vcpu), > > > + kvm_vcpu_is_be(source_vcpu)); > > > kvm_vcpu_wake_up(vcpu); > > > > > > return PSCI_RET_SUCCESS; > > > -- > > > 2.33.0.685.g46640cef36-goog > > > > Reviewed-by: Reiji Watanabe <reijiw@google.com> > > > > Not directly related to the patch, but the (original) code doesn't > > do any sanity checking for the entry address although the PSCI spec says: > > > > "INVALID_ADDRESS is returned when the entry point address is known > > by the implementation to be invalid, because it is in a range that > > is known not to be available to the caller." > > Right, I had noticed the same but was a tad too lazy to address in > this series :) Thanks for the review, Reji! > KVM doesn't reserve any subrange within [0 - max_ipa), afaik. So all we need to do is check 'entry_addr < max_ipa', right? Thanks, drew
On Thu, Sep 23, 2021 at 07:16:02PM +0000, Oliver Upton wrote: > In its implementation of the PSCI function, KVM needs to request that a > target vCPU resets before its next entry into the guest. Wrap the logic > for requesting a reset in a function for later use by other implemented > PSCI calls. > > No functional change intended. > > Signed-off-by: Oliver Upton <oupton@google.com> > --- > arch/arm64/kvm/psci.c | 59 +++++++++++++++++++++++++------------------ > 1 file changed, 35 insertions(+), 24 deletions(-) > > diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c > index 310b9cb2b32b..bb59b692998b 100644 > --- a/arch/arm64/kvm/psci.c > +++ b/arch/arm64/kvm/psci.c > @@ -64,9 +64,40 @@ static inline bool kvm_psci_valid_affinity(unsigned long affinity) > return !(affinity & ~MPIDR_HWID_BITMASK); > } > > -static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > +static void kvm_psci_vcpu_request_reset(struct kvm_vcpu *vcpu, > + unsigned long entry_addr, > + unsigned long context_id, > + bool big_endian) > { > struct vcpu_reset_state *reset_state; > + > + lockdep_assert_held(&vcpu->kvm->lock); > + > + reset_state = &vcpu->arch.reset_state; > + reset_state->pc = entry_addr; > + > + /* Propagate caller endianness */ > + reset_state->be = big_endian; > + > + /* > + * NOTE: We always update r0 (or x0) because for PSCI v0.1 > + * the general purpose registers are undefined upon CPU_ON. > + */ > + reset_state->r0 = context_id; > + > + WRITE_ONCE(reset_state->reset, true); > + kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > + > + /* > + * Make sure the reset request is observed if the change to > + * power_state is observed. > + */ > + smp_wmb(); > + vcpu->arch.power_off = false; > +} > + > +static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > +{ > struct kvm *kvm = source_vcpu->kvm; > struct kvm_vcpu *vcpu = NULL; > unsigned long cpu_id; > @@ -90,29 +121,9 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > return PSCI_RET_INVALID_PARAMS; > } > > - reset_state = &vcpu->arch.reset_state; > - > - reset_state->pc = smccc_get_arg2(source_vcpu); > - > - /* Propagate caller endianness */ > - reset_state->be = kvm_vcpu_is_be(source_vcpu); > - > - /* > - * NOTE: We always update r0 (or x0) because for PSCI v0.1 > - * the general purpose registers are undefined upon CPU_ON. > - */ > - reset_state->r0 = smccc_get_arg3(source_vcpu); > - > - WRITE_ONCE(reset_state->reset, true); > - kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > - > - /* > - * Make sure the reset request is observed if the change to > - * power_state is observed. > - */ > - smp_wmb(); > - > - vcpu->arch.power_off = false; > + kvm_psci_vcpu_request_reset(vcpu, smccc_get_arg2(source_vcpu), > + smccc_get_arg3(source_vcpu), > + kvm_vcpu_is_be(source_vcpu)); > kvm_vcpu_wake_up(vcpu); > > return PSCI_RET_SUCCESS; > -- > 2.33.0.685.g46640cef36-goog > Reviewed-by: Andrew Jones <drjones@redhat.com>
Hi folks, On Tue, Oct 5, 2021 at 6:33 AM Andrew Jones <drjones@redhat.com> wrote: > > On Fri, Oct 01, 2021 at 09:10:14AM -0700, Oliver Upton wrote: > > On Thu, Sep 30, 2021 at 11:05 PM Reiji Watanabe <reijiw@google.com> wrote: > > > > > > On Thu, Sep 23, 2021 at 12:16 PM Oliver Upton <oupton@google.com> wrote: > > > > > > > > In its implementation of the PSCI function, KVM needs to request that a > > > > target vCPU resets before its next entry into the guest. Wrap the logic > > > > for requesting a reset in a function for later use by other implemented > > > > PSCI calls. > > > > > > > > No functional change intended. > > > > > > > > Signed-off-by: Oliver Upton <oupton@google.com> > > > > --- > > > > arch/arm64/kvm/psci.c | 59 +++++++++++++++++++++++++------------------ > > > > 1 file changed, 35 insertions(+), 24 deletions(-) > > > > > > > > diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c > > > > index 310b9cb2b32b..bb59b692998b 100644 > > > > --- a/arch/arm64/kvm/psci.c > > > > +++ b/arch/arm64/kvm/psci.c > > > > @@ -64,9 +64,40 @@ static inline bool kvm_psci_valid_affinity(unsigned long affinity) > > > > return !(affinity & ~MPIDR_HWID_BITMASK); > > > > } > > > > > > > > -static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > > > +static void kvm_psci_vcpu_request_reset(struct kvm_vcpu *vcpu, > > > > + unsigned long entry_addr, > > > > + unsigned long context_id, > > > > + bool big_endian) > > > > { > > > > struct vcpu_reset_state *reset_state; > > > > + > > > > + lockdep_assert_held(&vcpu->kvm->lock); > > > > + > > > > + reset_state = &vcpu->arch.reset_state; > > > > + reset_state->pc = entry_addr; > > > > + > > > > + /* Propagate caller endianness */ > > > > + reset_state->be = big_endian; > > > > + > > > > + /* > > > > + * NOTE: We always update r0 (or x0) because for PSCI v0.1 > > > > + * the general purpose registers are undefined upon CPU_ON. > > > > + */ > > > > + reset_state->r0 = context_id; > > > > + > > > > + WRITE_ONCE(reset_state->reset, true); > > > > + kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > > > > + > > > > + /* > > > > + * Make sure the reset request is observed if the change to > > > > + * power_state is observed. > > > > + */ > > > > + smp_wmb(); > > > > + vcpu->arch.power_off = false; > > > > +} > > > > + > > > > +static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > > > +{ > > > > struct kvm *kvm = source_vcpu->kvm; > > > > struct kvm_vcpu *vcpu = NULL; > > > > unsigned long cpu_id; > > > > @@ -90,29 +121,9 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > > > return PSCI_RET_INVALID_PARAMS; > > > > } > > > > > > > > - reset_state = &vcpu->arch.reset_state; > > > > - > > > > - reset_state->pc = smccc_get_arg2(source_vcpu); > > > > - > > > > - /* Propagate caller endianness */ > > > > - reset_state->be = kvm_vcpu_is_be(source_vcpu); > > > > - > > > > - /* > > > > - * NOTE: We always update r0 (or x0) because for PSCI v0.1 > > > > - * the general purpose registers are undefined upon CPU_ON. > > > > - */ > > > > - reset_state->r0 = smccc_get_arg3(source_vcpu); > > > > - > > > > - WRITE_ONCE(reset_state->reset, true); > > > > - kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > > > > - > > > > - /* > > > > - * Make sure the reset request is observed if the change to > > > > - * power_state is observed. > > > > - */ > > > > - smp_wmb(); > > > > - > > > > - vcpu->arch.power_off = false; > > > > + kvm_psci_vcpu_request_reset(vcpu, smccc_get_arg2(source_vcpu), > > > > + smccc_get_arg3(source_vcpu), > > > > + kvm_vcpu_is_be(source_vcpu)); > > > > kvm_vcpu_wake_up(vcpu); > > > > > > > > return PSCI_RET_SUCCESS; > > > > -- > > > > 2.33.0.685.g46640cef36-goog > > > > > > Reviewed-by: Reiji Watanabe <reijiw@google.com> > > > > > > Not directly related to the patch, but the (original) code doesn't > > > do any sanity checking for the entry address although the PSCI spec says: > > > > > > "INVALID_ADDRESS is returned when the entry point address is known > > > by the implementation to be invalid, because it is in a range that > > > is known not to be available to the caller." > > > > Right, I had noticed the same but was a tad too lazy to address in > > this series :) Thanks for the review, Reji! > > > > KVM doesn't reserve any subrange within [0 - max_ipa), afaik. So all > we need to do is check 'entry_addr < max_ipa', right? > We could be a bit more pedantic and check if the IPA exists in a memory slot, seems like kvm_vcpu_is_visible_gfn() should do the trick. Thoughts? -- Thanks, Oliver
On Tue, Oct 05, 2021 at 08:05:02AM -0700, Oliver Upton wrote: > Hi folks, > > On Tue, Oct 5, 2021 at 6:33 AM Andrew Jones <drjones@redhat.com> wrote: > > > > On Fri, Oct 01, 2021 at 09:10:14AM -0700, Oliver Upton wrote: > > > On Thu, Sep 30, 2021 at 11:05 PM Reiji Watanabe <reijiw@google.com> wrote: > > > > > > > > On Thu, Sep 23, 2021 at 12:16 PM Oliver Upton <oupton@google.com> wrote: > > > > > > > > > > In its implementation of the PSCI function, KVM needs to request that a > > > > > target vCPU resets before its next entry into the guest. Wrap the logic > > > > > for requesting a reset in a function for later use by other implemented > > > > > PSCI calls. > > > > > > > > > > No functional change intended. > > > > > > > > > > Signed-off-by: Oliver Upton <oupton@google.com> > > > > > --- > > > > > arch/arm64/kvm/psci.c | 59 +++++++++++++++++++++++++------------------ > > > > > 1 file changed, 35 insertions(+), 24 deletions(-) > > > > > > > > > > diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c > > > > > index 310b9cb2b32b..bb59b692998b 100644 > > > > > --- a/arch/arm64/kvm/psci.c > > > > > +++ b/arch/arm64/kvm/psci.c > > > > > @@ -64,9 +64,40 @@ static inline bool kvm_psci_valid_affinity(unsigned long affinity) > > > > > return !(affinity & ~MPIDR_HWID_BITMASK); > > > > > } > > > > > > > > > > -static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > > > > +static void kvm_psci_vcpu_request_reset(struct kvm_vcpu *vcpu, > > > > > + unsigned long entry_addr, > > > > > + unsigned long context_id, > > > > > + bool big_endian) > > > > > { > > > > > struct vcpu_reset_state *reset_state; > > > > > + > > > > > + lockdep_assert_held(&vcpu->kvm->lock); > > > > > + > > > > > + reset_state = &vcpu->arch.reset_state; > > > > > + reset_state->pc = entry_addr; > > > > > + > > > > > + /* Propagate caller endianness */ > > > > > + reset_state->be = big_endian; > > > > > + > > > > > + /* > > > > > + * NOTE: We always update r0 (or x0) because for PSCI v0.1 > > > > > + * the general purpose registers are undefined upon CPU_ON. > > > > > + */ > > > > > + reset_state->r0 = context_id; > > > > > + > > > > > + WRITE_ONCE(reset_state->reset, true); > > > > > + kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > > > > > + > > > > > + /* > > > > > + * Make sure the reset request is observed if the change to > > > > > + * power_state is observed. > > > > > + */ > > > > > + smp_wmb(); > > > > > + vcpu->arch.power_off = false; > > > > > +} > > > > > + > > > > > +static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > > > > +{ > > > > > struct kvm *kvm = source_vcpu->kvm; > > > > > struct kvm_vcpu *vcpu = NULL; > > > > > unsigned long cpu_id; > > > > > @@ -90,29 +121,9 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > > > > return PSCI_RET_INVALID_PARAMS; > > > > > } > > > > > > > > > > - reset_state = &vcpu->arch.reset_state; > > > > > - > > > > > - reset_state->pc = smccc_get_arg2(source_vcpu); > > > > > - > > > > > - /* Propagate caller endianness */ > > > > > - reset_state->be = kvm_vcpu_is_be(source_vcpu); > > > > > - > > > > > - /* > > > > > - * NOTE: We always update r0 (or x0) because for PSCI v0.1 > > > > > - * the general purpose registers are undefined upon CPU_ON. > > > > > - */ > > > > > - reset_state->r0 = smccc_get_arg3(source_vcpu); > > > > > - > > > > > - WRITE_ONCE(reset_state->reset, true); > > > > > - kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > > > > > - > > > > > - /* > > > > > - * Make sure the reset request is observed if the change to > > > > > - * power_state is observed. > > > > > - */ > > > > > - smp_wmb(); > > > > > - > > > > > - vcpu->arch.power_off = false; > > > > > + kvm_psci_vcpu_request_reset(vcpu, smccc_get_arg2(source_vcpu), > > > > > + smccc_get_arg3(source_vcpu), > > > > > + kvm_vcpu_is_be(source_vcpu)); > > > > > kvm_vcpu_wake_up(vcpu); > > > > > > > > > > return PSCI_RET_SUCCESS; > > > > > -- > > > > > 2.33.0.685.g46640cef36-goog > > > > > > > > Reviewed-by: Reiji Watanabe <reijiw@google.com> > > > > > > > > Not directly related to the patch, but the (original) code doesn't > > > > do any sanity checking for the entry address although the PSCI spec says: > > > > > > > > "INVALID_ADDRESS is returned when the entry point address is known > > > > by the implementation to be invalid, because it is in a range that > > > > is known not to be available to the caller." > > > > > > Right, I had noticed the same but was a tad too lazy to address in > > > this series :) Thanks for the review, Reji! > > > > > > > KVM doesn't reserve any subrange within [0 - max_ipa), afaik. So all > > we need to do is check 'entry_addr < max_ipa', right? > > > > We could be a bit more pedantic and check if the IPA exists in a > memory slot, seems like kvm_vcpu_is_visible_gfn() should do the trick. > > Thoughts? Are we sure that all emulated devices, nvram, etc. will always use a memslot for regions that contain executable code? If there's any doubt, then we can't be sure about non-memslot regions within the max_ipa range. That'd be up to userspace. Thanks, drew
On Tue, Oct 5, 2021 at 12:02 PM Andrew Jones <drjones@redhat.com> wrote: > > On Tue, Oct 05, 2021 at 08:05:02AM -0700, Oliver Upton wrote: > > Hi folks, > > > > On Tue, Oct 5, 2021 at 6:33 AM Andrew Jones <drjones@redhat.com> wrote: > > > > > > On Fri, Oct 01, 2021 at 09:10:14AM -0700, Oliver Upton wrote: > > > > On Thu, Sep 30, 2021 at 11:05 PM Reiji Watanabe <reijiw@google.com> wrote: > > > > > > > > > > On Thu, Sep 23, 2021 at 12:16 PM Oliver Upton <oupton@google.com> wrote: > > > > > > > > > > > > In its implementation of the PSCI function, KVM needs to request that a > > > > > > target vCPU resets before its next entry into the guest. Wrap the logic > > > > > > for requesting a reset in a function for later use by other implemented > > > > > > PSCI calls. > > > > > > > > > > > > No functional change intended. > > > > > > > > > > > > Signed-off-by: Oliver Upton <oupton@google.com> > > > > > > --- > > > > > > arch/arm64/kvm/psci.c | 59 +++++++++++++++++++++++++------------------ > > > > > > 1 file changed, 35 insertions(+), 24 deletions(-) > > > > > > > > > > > > diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c > > > > > > index 310b9cb2b32b..bb59b692998b 100644 > > > > > > --- a/arch/arm64/kvm/psci.c > > > > > > +++ b/arch/arm64/kvm/psci.c > > > > > > @@ -64,9 +64,40 @@ static inline bool kvm_psci_valid_affinity(unsigned long affinity) > > > > > > return !(affinity & ~MPIDR_HWID_BITMASK); > > > > > > } > > > > > > > > > > > > -static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > > > > > +static void kvm_psci_vcpu_request_reset(struct kvm_vcpu *vcpu, > > > > > > + unsigned long entry_addr, > > > > > > + unsigned long context_id, > > > > > > + bool big_endian) > > > > > > { > > > > > > struct vcpu_reset_state *reset_state; > > > > > > + > > > > > > + lockdep_assert_held(&vcpu->kvm->lock); > > > > > > + > > > > > > + reset_state = &vcpu->arch.reset_state; > > > > > > + reset_state->pc = entry_addr; > > > > > > + > > > > > > + /* Propagate caller endianness */ > > > > > > + reset_state->be = big_endian; > > > > > > + > > > > > > + /* > > > > > > + * NOTE: We always update r0 (or x0) because for PSCI v0.1 > > > > > > + * the general purpose registers are undefined upon CPU_ON. > > > > > > + */ > > > > > > + reset_state->r0 = context_id; > > > > > > + > > > > > > + WRITE_ONCE(reset_state->reset, true); > > > > > > + kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > > > > > > + > > > > > > + /* > > > > > > + * Make sure the reset request is observed if the change to > > > > > > + * power_state is observed. > > > > > > + */ > > > > > > + smp_wmb(); > > > > > > + vcpu->arch.power_off = false; > > > > > > +} > > > > > > + > > > > > > +static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > > > > > +{ > > > > > > struct kvm *kvm = source_vcpu->kvm; > > > > > > struct kvm_vcpu *vcpu = NULL; > > > > > > unsigned long cpu_id; > > > > > > @@ -90,29 +121,9 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > > > > > > return PSCI_RET_INVALID_PARAMS; > > > > > > } > > > > > > > > > > > > - reset_state = &vcpu->arch.reset_state; > > > > > > - > > > > > > - reset_state->pc = smccc_get_arg2(source_vcpu); > > > > > > - > > > > > > - /* Propagate caller endianness */ > > > > > > - reset_state->be = kvm_vcpu_is_be(source_vcpu); > > > > > > - > > > > > > - /* > > > > > > - * NOTE: We always update r0 (or x0) because for PSCI v0.1 > > > > > > - * the general purpose registers are undefined upon CPU_ON. > > > > > > - */ > > > > > > - reset_state->r0 = smccc_get_arg3(source_vcpu); > > > > > > - > > > > > > - WRITE_ONCE(reset_state->reset, true); > > > > > > - kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); > > > > > > - > > > > > > - /* > > > > > > - * Make sure the reset request is observed if the change to > > > > > > - * power_state is observed. > > > > > > - */ > > > > > > - smp_wmb(); > > > > > > - > > > > > > - vcpu->arch.power_off = false; > > > > > > + kvm_psci_vcpu_request_reset(vcpu, smccc_get_arg2(source_vcpu), > > > > > > + smccc_get_arg3(source_vcpu), > > > > > > + kvm_vcpu_is_be(source_vcpu)); > > > > > > kvm_vcpu_wake_up(vcpu); > > > > > > > > > > > > return PSCI_RET_SUCCESS; > > > > > > -- > > > > > > 2.33.0.685.g46640cef36-goog > > > > > > > > > > Reviewed-by: Reiji Watanabe <reijiw@google.com> > > > > > > > > > > Not directly related to the patch, but the (original) code doesn't > > > > > do any sanity checking for the entry address although the PSCI spec says: > > > > > > > > > > "INVALID_ADDRESS is returned when the entry point address is known > > > > > by the implementation to be invalid, because it is in a range that > > > > > is known not to be available to the caller." > > > > > > > > Right, I had noticed the same but was a tad too lazy to address in > > > > this series :) Thanks for the review, Reji! > > > > > > > > > > KVM doesn't reserve any subrange within [0 - max_ipa), afaik. So all > > > we need to do is check 'entry_addr < max_ipa', right? > > > > > > > We could be a bit more pedantic and check if the IPA exists in a > > memory slot, seems like kvm_vcpu_is_visible_gfn() should do the trick. > > > > Thoughts? > > Are we sure that all emulated devices, nvram, etc. will always use a > memslot for regions that contain executable code? If there's any doubt, > then we can't be sure about non-memslot regions within the max_ipa range. > That'd be up to userspace. I'm sorry for the late response. IMHO, I would prefer Andrew's suggestion (check with the max_ipa). It looks like instructions must always be in memslot for KVM/ARM looking at the current implementation (especially kvm_handle_guest_abort()). But, it doesn't necessarily mean the address is not invalid for the guest (could be valid for load/store) and it might be changed in the future. Thanks, Reiji
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c index 310b9cb2b32b..bb59b692998b 100644 --- a/arch/arm64/kvm/psci.c +++ b/arch/arm64/kvm/psci.c @@ -64,9 +64,40 @@ static inline bool kvm_psci_valid_affinity(unsigned long affinity) return !(affinity & ~MPIDR_HWID_BITMASK); } -static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) +static void kvm_psci_vcpu_request_reset(struct kvm_vcpu *vcpu, + unsigned long entry_addr, + unsigned long context_id, + bool big_endian) { struct vcpu_reset_state *reset_state; + + lockdep_assert_held(&vcpu->kvm->lock); + + reset_state = &vcpu->arch.reset_state; + reset_state->pc = entry_addr; + + /* Propagate caller endianness */ + reset_state->be = big_endian; + + /* + * NOTE: We always update r0 (or x0) because for PSCI v0.1 + * the general purpose registers are undefined upon CPU_ON. + */ + reset_state->r0 = context_id; + + WRITE_ONCE(reset_state->reset, true); + kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); + + /* + * Make sure the reset request is observed if the change to + * power_state is observed. + */ + smp_wmb(); + vcpu->arch.power_off = false; +} + +static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) +{ struct kvm *kvm = source_vcpu->kvm; struct kvm_vcpu *vcpu = NULL; unsigned long cpu_id; @@ -90,29 +121,9 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) return PSCI_RET_INVALID_PARAMS; } - reset_state = &vcpu->arch.reset_state; - - reset_state->pc = smccc_get_arg2(source_vcpu); - - /* Propagate caller endianness */ - reset_state->be = kvm_vcpu_is_be(source_vcpu); - - /* - * NOTE: We always update r0 (or x0) because for PSCI v0.1 - * the general purpose registers are undefined upon CPU_ON. - */ - reset_state->r0 = smccc_get_arg3(source_vcpu); - - WRITE_ONCE(reset_state->reset, true); - kvm_make_request(KVM_REQ_VCPU_RESET, vcpu); - - /* - * Make sure the reset request is observed if the change to - * power_state is observed. - */ - smp_wmb(); - - vcpu->arch.power_off = false; + kvm_psci_vcpu_request_reset(vcpu, smccc_get_arg2(source_vcpu), + smccc_get_arg3(source_vcpu), + kvm_vcpu_is_be(source_vcpu)); kvm_vcpu_wake_up(vcpu); return PSCI_RET_SUCCESS;
In its implementation of the PSCI function, KVM needs to request that a target vCPU resets before its next entry into the guest. Wrap the logic for requesting a reset in a function for later use by other implemented PSCI calls. No functional change intended. Signed-off-by: Oliver Upton <oupton@google.com> --- arch/arm64/kvm/psci.c | 59 +++++++++++++++++++++++++------------------ 1 file changed, 35 insertions(+), 24 deletions(-)