On Mon, Sep 02, 2024 at 02:42:19PM GMT, Tom Dohrmann wrote:
> Until recently, KVM_CAP_READONLY_MEM was unconditionally supported on
> x86, but this is no longer the case for SEV-ES and SEV-SNP VMs.
>
> When KVM_CHECK_EXTENSION is invoked on a VM, only advertise
> KVM_CAP_READONLY_MEM when it's actually supported.
>
> Fixes: 66155de93bcf ("KVM: x86: Disallow read-only memslots for SEV-ES and SEV-SNP (and TDX)")
> Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Cc: Michael Roth <michael.roth@xxxxxxx>
> Signed-off-by: Tom Dohrmann <erbse.13@xxxxxx>
> ---
> arch/x86/kvm/x86.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 70219e406987..9ad7fe279e72 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -4656,7 +4656,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
> case KVM_CAP_ASYNC_PF_INT:
> case KVM_CAP_GET_TSC_KHZ:
> case KVM_CAP_KVMCLOCK_CTRL:
> - case KVM_CAP_READONLY_MEM:
> case KVM_CAP_IOAPIC_POLARITY_IGNORED:
> case KVM_CAP_TSC_DEADLINE_TIMER:
> case KVM_CAP_DISABLE_QUIRKS:
> @@ -4815,6 +4814,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
> case KVM_CAP_VM_TYPES:
> r = kvm_caps.supported_vm_types;
> break;
> + case KVM_CAP_READONLY_MEM:
> + r = kvm ? kvm_arch_has_readonly_mem(kvm) : 1;
Need a break here otherwise -Wimplicit-fallthrough option will warn.
> default:
> break;
> }
> --
> 2.34.1
