[PATCH v2 1/5] KVM: x86: Introduce KVM_REQ_RING_SOFT_FULL
From: Gavin Shan <hidden>
Date: 2022-09-16 04:52:06
Also in:
kvm, kvmarm, linux-doc, linux-kselftest, lkml
Subsystem:
kernel virtual machine (kvm), kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Paolo Bonzini, Sean Christopherson, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
This adds KVM_REQ_RING_SOFT_FULL, which is raised when the dirty ring of the specific VCPU becomes softly full in kvm_dirty_ring_push(). The VCPU is enforced to exit when the request is raised and its dirty ring is softly full on its entrance. Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Gavin Shan <redacted> --- arch/x86/kvm/x86.c | 5 +++-- include/linux/kvm_host.h | 1 + virt/kvm/dirty_ring.c | 4 ++++ 3 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 43a6a7efc6ec..7f368f59f033 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c@@ -10265,8 +10265,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) bool req_immediate_exit = false; /* Forbid vmenter if vcpu dirty ring is soft-full */ - if (unlikely(vcpu->kvm->dirty_ring_size && - kvm_dirty_ring_soft_full(&vcpu->dirty_ring))) { + if (kvm_check_request(KVM_REQ_RING_SOFT_FULL, vcpu) && + kvm_dirty_ring_soft_full(&vcpu->dirty_ring)) { + kvm_make_request(KVM_REQ_RING_SOFT_FULL, vcpu); vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL; trace_kvm_dirty_ring_exit(vcpu); r = 0;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index f4519d3689e1..53fa3134fee0 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h@@ -157,6 +157,7 @@ static inline bool is_error_page(struct page *page) #define KVM_REQ_VM_DEAD (1 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) #define KVM_REQ_UNBLOCK 2 #define KVM_REQ_UNHALT 3 +#define KVM_REQ_RING_SOFT_FULL 4 #define KVM_REQUEST_ARCH_BASE 8 /*
diff --git a/virt/kvm/dirty_ring.c b/virt/kvm/dirty_ring.c
index f4c2a6eb1666..f0e49937bc9e 100644
--- a/virt/kvm/dirty_ring.c
+++ b/virt/kvm/dirty_ring.c@@ -149,6 +149,7 @@ int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring) void kvm_dirty_ring_push(struct kvm_dirty_ring *ring, u32 slot, u64 offset) { + struct kvm_vcpu *vcpu = container_of(ring, struct kvm_vcpu, dirty_ring); struct kvm_dirty_gfn *entry; /* It should never get full */
@@ -166,6 +167,9 @@ void kvm_dirty_ring_push(struct kvm_dirty_ring *ring, u32 slot, u64 offset) kvm_dirty_gfn_set_dirtied(entry); ring->dirty_index++; trace_kvm_dirty_ring_push(ring, slot, offset); + + if (kvm_dirty_ring_soft_full(ring)) + kvm_make_request(KVM_REQ_RING_SOFT_FULL, vcpu); } struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring, u32 offset)
--
2.23.0
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