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| author | Oliver Upton <oliver.upton@linux.dev> | 2023-09-20 22:50:29 +0300 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-09-21 21:13:28 +0300 |
| commit | ef150908b6bd80a54126dbec324bd63a24a5628a (patch) | |
| tree | 37e1e706dd81baa3d1e81c3a9433a80622ecc1f9 /arch/arm64/kvm/arm.c | |
| parent | ce9ecca0238b140b88f43859b211c9fdfd8e5b70 (diff) | |
| download | linux-ef150908b6bd80a54126dbec324bd63a24a5628a.tar.xz | |
KVM: arm64: Add generic check for system-supported vCPU features
To date KVM has relied on kvm_reset_vcpu() failing when the vCPU feature
flags are unsupported by the system. This is a bit messy since
kvm_reset_vcpu() is called at runtime outside of the KVM_ARM_VCPU_INIT
ioctl when it is expected to succeed. Further complicating the matter is
that kvm_reset_vcpu() must tolerate be idemptotent to the config_lock,
as it isn't consistently called with the lock held.
Prepare to move feature compatibility checks out of kvm_reset_vcpu() with
a 'generic' check that compares the user-provided flags with a computed
maximum feature set for the system.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20230920195036.1169791-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/kvm/arm.c')
| -rw-r--r-- | arch/arm64/kvm/arm.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 4866b3f7b4ea..8b5094343f84 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1190,6 +1190,16 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level, return -EINVAL; } +static unsigned long system_supported_vcpu_features(void) +{ + unsigned long features = KVM_VCPU_VALID_FEATURES; + + if (!cpus_have_final_cap(ARM64_HAS_32BIT_EL1)) + clear_bit(KVM_ARM_VCPU_EL1_32BIT, &features); + + return features; +} + static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu, const struct kvm_vcpu_init *init) { @@ -1204,12 +1214,12 @@ static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu, return -ENOENT; } + if (features & ~system_supported_vcpu_features()) + return -EINVAL; + if (!test_bit(KVM_ARM_VCPU_EL1_32BIT, &features)) return 0; - if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1)) - return -EINVAL; - /* MTE is incompatible with AArch32 */ if (kvm_has_mte(vcpu->kvm)) return -EINVAL; |