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authorPaolo Bonzini <pbonzini@redhat.com>2022-10-03 15:33:32 -0400
committerPaolo Bonzini <pbonzini@redhat.com>2022-10-03 15:33:32 -0400
commitfe4d9e4abf622598bd199d0805d20afa12f70c92 (patch)
treeccb8d2aff2c311be6a316a77c1955a8dac9749b8 /virt
parente779ce9d17c44a338b4fa3be8715e3b7eb9706f0 (diff)
parentb302ca52ba8235ff0e18c0fa1fa92b51784aef6a (diff)
Merge tag 'kvmarm-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for v6.1 - Fixes for single-stepping in the presence of an async exception as well as the preservation of PSTATE.SS - Better handling of AArch32 ID registers on AArch64-only systems - Fixes for the dirty-ring API, allowing it to work on architectures with relaxed memory ordering - Advertise the new kvmarm mailing list - Various minor cleanups and spelling fixes
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/Kconfig14
-rw-r--r--virt/kvm/dirty_ring.c4
-rw-r--r--virt/kvm/kvm_main.c9
3 files changed, 24 insertions, 3 deletions
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index a8c5c9f06b3c..800f9470e36b 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -19,6 +19,20 @@ config HAVE_KVM_IRQ_ROUTING
config HAVE_KVM_DIRTY_RING
bool
+# Only strongly ordered architectures can select this, as it doesn't
+# put any explicit constraint on userspace ordering. They can also
+# select the _ACQ_REL version.
+config HAVE_KVM_DIRTY_RING_TSO
+ bool
+ select HAVE_KVM_DIRTY_RING
+ depends on X86
+
+# Weakly ordered architectures can only select this, advertising
+# to userspace the additional ordering requirements.
+config HAVE_KVM_DIRTY_RING_ACQ_REL
+ bool
+ select HAVE_KVM_DIRTY_RING
+
config HAVE_KVM_EVENTFD
bool
select EVENTFD
diff --git a/virt/kvm/dirty_ring.c b/virt/kvm/dirty_ring.c
index f4c2a6eb1666..d6fabf238032 100644
--- a/virt/kvm/dirty_ring.c
+++ b/virt/kvm/dirty_ring.c
@@ -74,7 +74,7 @@ int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size)
static inline void kvm_dirty_gfn_set_invalid(struct kvm_dirty_gfn *gfn)
{
- gfn->flags = 0;
+ smp_store_release(&gfn->flags, 0);
}
static inline void kvm_dirty_gfn_set_dirtied(struct kvm_dirty_gfn *gfn)
@@ -84,7 +84,7 @@ static inline void kvm_dirty_gfn_set_dirtied(struct kvm_dirty_gfn *gfn)
static inline bool kvm_dirty_gfn_harvested(struct kvm_dirty_gfn *gfn)
{
- return gfn->flags & KVM_DIRTY_GFN_F_RESET;
+ return smp_load_acquire(&gfn->flags) & KVM_DIRTY_GFN_F_RESET;
}
int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 26383e63d9dd..e30f1b4ecfa5 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4473,7 +4473,13 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
case KVM_CAP_NR_MEMSLOTS:
return KVM_USER_MEM_SLOTS;
case KVM_CAP_DIRTY_LOG_RING:
-#ifdef CONFIG_HAVE_KVM_DIRTY_RING
+#ifdef CONFIG_HAVE_KVM_DIRTY_RING_TSO
+ return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn);
+#else
+ return 0;
+#endif
+ case KVM_CAP_DIRTY_LOG_RING_ACQ_REL:
+#ifdef CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL
return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn);
#else
return 0;
@@ -4578,6 +4584,7 @@ static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm,
return 0;
}
case KVM_CAP_DIRTY_LOG_RING:
+ case KVM_CAP_DIRTY_LOG_RING_ACQ_REL:
return kvm_vm_ioctl_enable_dirty_log_ring(kvm, cap->args[0]);
default:
return kvm_vm_ioctl_enable_cap(kvm, cap);