KVM: PPC: Return '1' unconditionally for KVM_CAP_SYNC_MMU

Advertise that KVM's MMU is synchronized with the primary MMU for all
flavors of PPC KVM support, i.e. advertise that the MMU is synchronized
when CONFIG_KVM_BOOK3S_HV_POSSIBLE=y but the VM is not using hypervisor
mode (a.k.a. PR VMs).  PR VMs, via kvm_unmap_gfn_range_pr(), do the right
thing for mmu_notifier invalidation events, and more tellingly, KVM
returns '1' for KVM_CAP_SYNC_MMU when CONFIG_KVM_BOOK3S_HV_POSSIBLE=n
and CONFIG_KVM_BOOK3S_PR_POSSIBLE=y, i.e. KVM already advertises a
synchronized MMU for PR VMs, just not when CONFIG_KVM_BOOK3S_HV_POSSIBLE=y.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20231027182217.3615211-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index b0a512ede764f6ddeb51af9a585b13c93d8bedfe..8d3ec483bc2b203ca162401c8a5afea0d919ca0e 100644 (file)
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -635,11 +635,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 #if !defined(CONFIG_MMU_NOTIFIER) || !defined(KVM_ARCH_WANT_MMU_NOTIFIER)
                BUILD_BUG();
 #endif
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-               r = hv_enabled;
-#else
                r = 1;
-#endif
                break;
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
        case KVM_CAP_PPC_HTAB_FD: