From 9cb1096f8590bc590326087bea65db932b53c3b5 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Thu, 10 Nov 2022 18:49:11 +0800 Subject: [PATCH] KVM: arm64: Enable ring-based dirty memory tracking Enable ring-based dirty memory tracking on ARM64: - Enable CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL. - Enable CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP. - Set KVM_DIRTY_LOG_PAGE_OFFSET for the ring buffer's physical page offset. - Add ARM64 specific kvm_arch_allow_write_without_running_vcpu() to keep the site of saving vgic/its tables out of the no-running-vcpu radar. Signed-off-by: Gavin Shan Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20221110104914.31280-5-gshan@redhat.com --- 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/vgic/vgic-its.c | 20 ++++++++++++++++++++ include/kvm/arm_vgic.h | 1 + 6 files changed, 28 insertions(+), 1 deletion(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 1f1b09aa6db4..773e4b202f47 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..05da3c8f7e88 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 NEED_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/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index 733b53055f97..94a666dd1443 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); @@ -2775,6 +2778,23 @@ static int vgic_its_ctrl(struct kvm *kvm, struct vgic_its *its, u64 attr) return ret; } +/* + * 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) +{ + struct vgic_dist *dist = &kvm->arch.vgic; + + return dist->save_its_tables_in_progress; +} + static int vgic_its_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 4df9e73a8bb5..9270cd87da3f 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. -- 2.25.1