Enable ring-based dirty memory tracking on arm64 by selecting
CONFIG_HAVE_KVM_DIRTY_{RING_ACQ_REL, RING_WITH_BITMAP} and providing
the ring buffer's physical page offset (KVM_DIRTY_LOG_PAGE_OFFSET).
Besides, helper kvm_vgic_save_its_tables_in_progress() is added to
indicate if vgic/its tables are being saved or not. The helper is used
in ARM64's kvm_arch_allow_write_without_running_vcpu() to keep the
site of saving vgic/its tables out of no-running-vcpu radar.
Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
---
Documentation/virt/kvm/api.rst | 2 +-
arch/arm64/include/uapi/asm/kvm.h | 1 +
arch/arm64/kvm/Kconfig | 2 ++
arch/arm64/kvm/arm.c | 3 +++
arch/arm64/kvm/mmu.c | 15 +++++++++++++++
arch/arm64/kvm/vgic/vgic-its.c | 3 +++
arch/arm64/kvm/vgic/vgic-mmio-v3.c | 7 +++++++
include/kvm/arm_vgic.h | 2 ++
8 files changed, 34 insertions(+), 1 deletion(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 2ec32bd41792..2fc68f684ad8 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -7921,7 +7921,7 @@ regardless of what has actually been exposed through the CPUID leaf.
8.29 KVM_CAP_DIRTY_LOG_RING/KVM_CAP_DIRTY_LOG_RING_ACQ_REL
----------------------------------------------------------
-:Architectures: x86
+:Architectures: x86, arm64
:Parameters: args[0] - size of the dirty log ring
KVM is capable of tracking dirty memory using ring buffers that are
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 316917b98707..a7a857f1784d 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -43,6 +43,7 @@
#define __KVM_HAVE_VCPU_EVENTS
#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
+#define KVM_DIRTY_LOG_PAGE_OFFSET 64
#define KVM_REG_SIZE(id) \
(1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT))
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 815cc118c675..066b053e9eb9 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -32,6 +32,8 @@ menuconfig KVM
select KVM_VFIO
select HAVE_KVM_EVENTFD
select HAVE_KVM_IRQFD
+ select HAVE_KVM_DIRTY_RING_ACQ_REL
+ select HAVE_KVM_DIRTY_RING_WITH_BITMAP
select HAVE_KVM_MSI
select HAVE_KVM_IRQCHIP
select HAVE_KVM_IRQ_ROUTING
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 94d33e296e10..6b097605e38c 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -746,6 +746,9 @@ static int check_vcpu_requests(struct kvm_vcpu *vcpu)
if (kvm_check_request(KVM_REQ_SUSPEND, vcpu))
return kvm_vcpu_suspend(vcpu);
+
+ if (kvm_dirty_ring_check_request(vcpu))
+ return 0;
}
return 1;
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 60ee3d9f01f8..fbeb55e45f53 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -932,6 +932,21 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
}
+/*
+ * kvm_arch_allow_write_without_running_vcpu - allow writing guest memory
+ * without the running VCPU when dirty ring is enabled.
+ *
+ * The running VCPU is required to track dirty guest pages when dirty ring
+ * is enabled. Otherwise, the backup bitmap should be used to track the
+ * dirty guest pages. When vgic/its tables are being saved, the backup
+ * bitmap is used to track the dirty guest pages due to the missed running
+ * VCPU in the period.
+ */
+bool kvm_arch_allow_write_without_running_vcpu(struct kvm *kvm)
+{
+ return kvm_vgic_save_its_tables_in_progress(kvm);
+}
+
static void kvm_send_hwpoison_signal(unsigned long address, short lsb)
{
send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb, current);
diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 733b53055f97..dd340bb812bd 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -2743,6 +2743,7 @@ static int vgic_its_has_attr(struct kvm_device *dev,
static int vgic_its_ctrl(struct kvm *kvm, struct vgic_its *its, u64 attr)
{
const struct vgic_its_abi *abi = vgic_its_get_abi(its);
+ struct vgic_dist *dist = &kvm->arch.vgic;
int ret = 0;
if (attr == KVM_DEV_ARM_VGIC_CTRL_INIT) /* Nothing to do */
@@ -2762,7 +2763,9 @@ static int vgic_its_ctrl(struct kvm *kvm, struct vgic_its *its, u64 attr)
vgic_its_reset(kvm, its);
break;
case KVM_DEV_ARM_ITS_SAVE_TABLES:
+ dist->save_its_tables_in_progress = true;
ret = abi->save_tables(its);
+ dist->save_its_tables_in_progress = false;
break;
case KVM_DEV_ARM_ITS_RESTORE_TABLES:
ret = abi->restore_tables(its);
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index 91201f743033..b63898f86e9e 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -54,6 +54,13 @@ bool vgic_supports_direct_msis(struct kvm *kvm)
(kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm)));
}
+bool kvm_vgic_save_its_tables_in_progress(struct kvm *kvm)
+{
+ struct vgic_dist *dist = &kvm->arch.vgic;
+
+ return dist->save_its_tables_in_progress;
+}
+
/*
* The Revision field in the IIDR have the following meanings:
*
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 4df9e73a8bb5..db42fbd47bcf 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -263,6 +263,7 @@ struct vgic_dist {
struct vgic_io_device dist_iodev;
bool has_its;
+ bool save_its_tables_in_progress;
/*
* Contains the attributes and gpa of the LPI configuration table.
@@ -374,6 +375,7 @@ int kvm_vgic_map_resources(struct kvm *kvm);
int kvm_vgic_hyp_init(void);
void kvm_vgic_init_cpu_hardware(void);
+bool kvm_vgic_save_its_tables_in_progress(struct kvm *kvm);
int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
bool level, void *owner);
int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, unsigned int host_irq,
--
2.23.0
