| Message ID | 20210923191610.3814698-3-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: > > The only valid calling SMC calling convention from an AArch32 state is > SMC32. Disallow any PSCI function that sets the SMC64 function ID bit > when called from AArch32 rather than comparing against known SMC64 PSCI > functions. > > Signed-off-by: Oliver Upton <oupton@google.com> Looks nice. Reviewed-by: Reiji Watanabe <reijiw@google.com>
On Thu, Sep 23, 2021 at 07:16:01PM +0000, Oliver Upton wrote: > The only valid calling SMC calling convention from an AArch32 state is > SMC32. Disallow any PSCI function that sets the SMC64 function ID bit > when called from AArch32 rather than comparing against known SMC64 PSCI > functions. > > Signed-off-by: Oliver Upton <oupton@google.com> > --- > arch/arm64/kvm/psci.c | 14 +++++--------- > 1 file changed, 5 insertions(+), 9 deletions(-) > > diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c > index d46842f45b0a..310b9cb2b32b 100644 > --- a/arch/arm64/kvm/psci.c > +++ b/arch/arm64/kvm/psci.c > @@ -208,15 +208,11 @@ static void kvm_psci_narrow_to_32bit(struct kvm_vcpu *vcpu) > > static unsigned long kvm_psci_check_allowed_function(struct kvm_vcpu *vcpu, u32 fn) > { > - switch(fn) { > - case PSCI_0_2_FN64_CPU_SUSPEND: > - case PSCI_0_2_FN64_CPU_ON: > - case PSCI_0_2_FN64_AFFINITY_INFO: > - /* Disallow these functions for 32bit guests */ > - if (vcpu_mode_is_32bit(vcpu)) > - return PSCI_RET_NOT_SUPPORTED; > - break; > - } > + /* > + * Prevent 32 bit guests from calling 64 bit PSCI functions. > + */ > + if ((fn & PSCI_0_2_64BIT) && vcpu_mode_is_32bit(vcpu)) > + return PSCI_RET_NOT_SUPPORTED; > > return 0; > } > -- > 2.33.0.685.g46640cef36-goog > Reviewed-by: Andrew Jones <drjones@redhat.com>
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c index d46842f45b0a..310b9cb2b32b 100644 --- a/arch/arm64/kvm/psci.c +++ b/arch/arm64/kvm/psci.c @@ -208,15 +208,11 @@ static void kvm_psci_narrow_to_32bit(struct kvm_vcpu *vcpu) static unsigned long kvm_psci_check_allowed_function(struct kvm_vcpu *vcpu, u32 fn) { - switch(fn) { - case PSCI_0_2_FN64_CPU_SUSPEND: - case PSCI_0_2_FN64_CPU_ON: - case PSCI_0_2_FN64_AFFINITY_INFO: - /* Disallow these functions for 32bit guests */ - if (vcpu_mode_is_32bit(vcpu)) - return PSCI_RET_NOT_SUPPORTED; - break; - } + /* + * Prevent 32 bit guests from calling 64 bit PSCI functions. + */ + if ((fn & PSCI_0_2_64BIT) && vcpu_mode_is_32bit(vcpu)) + return PSCI_RET_NOT_SUPPORTED; return 0; }
The only valid calling SMC calling convention from an AArch32 state is SMC32. Disallow any PSCI function that sets the SMC64 function ID bit when called from AArch32 rather than comparing against known SMC64 PSCI functions. Signed-off-by: Oliver Upton <oupton@google.com> --- arch/arm64/kvm/psci.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-)