Re: [PATCH 1/8] KVM: arm64: Add generic check for system-supported vCPU features

Philippe Mathieu-Daudé
2023-09-21T17:25:34Z

On 20/9/23 21:50, Oliver Upton wrote:
> 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.
>
> Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
> ---
> arch/arm64/kvm/arm.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>