Restrict protected VM capabilities based on the fixed-configuration for protected VMs.
No functional change intended in current KVM-supported modes (nVHE, VHE). Signed-off-by: Fuad Tabba <[email protected]> --- arch/arm64/include/asm/kvm_fixed_config.h | 10 ++++ arch/arm64/kvm/arm.c | 63 ++++++++++++++++++++++- arch/arm64/kvm/pkvm.c | 30 +++++++++++ 3 files changed, 102 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_fixed_config.h b/arch/arm64/include/asm/kvm_fixed_config.h index b39a5de2c4b9..14310b035bf7 100644 --- a/arch/arm64/include/asm/kvm_fixed_config.h +++ b/arch/arm64/include/asm/kvm_fixed_config.h @@ -175,4 +175,14 @@ */ #define PVM_ID_AA64ISAR1_ALLOW (~0ULL) +/* + * Returns the maximum number of breakpoints supported for protected VMs. + */ +int kvm_arm_pkvm_get_max_brps(void); + +/* + * Returns the maximum number of watchpoints supported for protected VMs. + */ +int kvm_arm_pkvm_get_max_wrps(void); + #endif /* __ARM64_KVM_FIXED_CONFIG_H__ */ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 3f28549aff0d..bc41e3b71fab 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -34,6 +34,7 @@ #include <asm/virt.h> #include <asm/kvm_arm.h> #include <asm/kvm_asm.h> +#include <asm/kvm_fixed_config.h> #include <asm/kvm_mmu.h> #include <asm/kvm_emulate.h> #include <asm/sections.h> @@ -188,9 +189,10 @@ void kvm_arch_destroy_vm(struct kvm *kvm) atomic_set(&kvm->online_vcpus, 0); } -int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) +static int kvm_check_extension(struct kvm *kvm, long ext) { int r; + switch (ext) { case KVM_CAP_IRQCHIP: r = vgic_present; @@ -281,6 +283,65 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) return r; } +static int pkvm_check_extension(struct kvm *kvm, long ext, int kvm_cap) +{ + int r; + + switch (ext) { + case KVM_CAP_ARM_PSCI: + case KVM_CAP_ARM_PSCI_0_2: + case KVM_CAP_NR_VCPUS: + case KVM_CAP_MAX_VCPUS: + case KVM_CAP_MAX_VCPU_ID: + r = kvm_cap; + break; + case KVM_CAP_ARM_EL1_32BIT: + r = kvm_cap && + (FIELD_GET(FEATURE(ID_AA64PFR0_EL1), PVM_ID_AA64PFR0_ALLOW) >= + ID_AA64PFR0_ELx_32BIT_64BIT); + break; + case KVM_CAP_GUEST_DEBUG_HW_BPS: + r = min(kvm_cap, kvm_arm_pkvm_get_max_brps()); + break; + case KVM_CAP_GUEST_DEBUG_HW_WPS: + r = min(kvm_cap, kvm_arm_pkvm_get_max_wrps()); + break; + case KVM_CAP_ARM_PMU_V3: + r = kvm_cap && + FIELD_GET(FEATURE(ID_AA64DFR0_PMUVER), PVM_ID_AA64DFR0_ALLOW); + break; + case KVM_CAP_ARM_SVE: + r = kvm_cap && + FIELD_GET(FEATURE(ID_AA64PFR0_SVE), PVM_ID_AA64PFR0_ALLOW); + break; + case KVM_CAP_ARM_PTRAUTH_ADDRESS: + r = kvm_cap && + FIELD_GET(FEATURE(ID_AA64ISAR1_API), PVM_ID_AA64ISAR1_ALLOW) && + FIELD_GET(FEATURE(ID_AA64ISAR1_APA), PVM_ID_AA64ISAR1_ALLOW); + break; + case KVM_CAP_ARM_PTRAUTH_GENERIC: + r = kvm_cap && + FIELD_GET(FEATURE(ID_AA64ISAR1_GPI), PVM_ID_AA64ISAR1_ALLOW) && + FIELD_GET(FEATURE(ID_AA64ISAR1_GPA), PVM_ID_AA64ISAR1_ALLOW); + break; + default: + r = 0; + break; + } + + return r; +} + +int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) +{ + int r = kvm_check_extension(kvm, ext); + + if (unlikely(kvm && kvm_vm_is_protected(kvm))) + r = pkvm_check_extension(kvm, ext, r); + + return r; +} + long kvm_arch_dev_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index b8430b3d97af..d41553594d08 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -181,3 +181,33 @@ void kvm_init_protected_traps(struct kvm_vcpu *vcpu) pvm_init_traps_aa64mmfr0(vcpu); pvm_init_traps_aa64mmfr1(vcpu); } + +int kvm_arm_pkvm_get_max_brps(void) +{ + int num = FIELD_GET(FEATURE(ID_AA64DFR0_BRPS), PVM_ID_AA64DFR0_ALLOW); + + /* + * If breakpoints are supported, the maximum number is 1 + the field. + * Otherwise, return 0, which is not compliant with the architecture, + * but is reserved and is used here to indicate no debug support. + */ + if (num) + return 1 + num; + else + return 0; +} + +int kvm_arm_pkvm_get_max_wrps(void) +{ + int num = FIELD_GET(FEATURE(ID_AA64DFR0_WRPS), PVM_ID_AA64DFR0_ALLOW); + + /* + * If breakpoints are supported, the maximum number is 1 + the field. + * Otherwise, return 0, which is not compliant with the architecture, + * but is reserved and is used here to indicate no debug support. + */ + if (num) + return 1 + num; + else + return 0; +} -- 2.32.0.402.g57bb445576-goog _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
