* [PATCH 05/14] KVM: X86: Implement ring-based dirty memory tracking
2020-02-05 2:58 ` [PATCH 04/14] KVM: Pass in kvm pointer into mark_page_dirty_in_slot() Peter Xu
@ 2020-02-05 2:58 ` Peter Xu
2020-02-05 2:58 ` [PATCH 06/14] KVM: Make dirty ring exclusive to dirty bitmap log Peter Xu
` (7 subsequent siblings)
8 siblings, 0 replies; 25+ messages in thread
From: Peter Xu @ 2020-02-05 2:58 UTC (permalink / raw)
To: kvm, linux-kernel
Cc: dinechin, sean.j.christopherson, pbonzini, jasowang, yan.y.zhao,
mst, peterx, kevin.tian, alex.williamson, dgilbert, vkuznets,
Lei Cao
This patch is heavily based on previous work from Lei Cao
<lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1]
KVM currently uses large bitmaps to track dirty memory. These bitmaps
are copied to userspace when userspace queries KVM for its dirty page
information. The use of bitmaps is mostly sufficient for live
migration, as large parts of memory are be dirtied from one log-dirty
pass to another. However, in a checkpointing system, the number of
dirty pages is small and in fact it is often bounded---the VM is
paused when it has dirtied a pre-defined number of pages. Traversing a
large, sparsely populated bitmap to find set bits is time-consuming,
as is copying the bitmap to user-space.
A similar issue will be there for live migration when the guest memory
is huge while the page dirty procedure is trivial. In that case for
each dirty sync we need to pull the whole dirty bitmap to userspace
and analyse every bit even if it's mostly zeros.
The preferred data structure for above scenarios is a dense list of
guest frame numbers (GFN). This patch series stores the dirty list in
kernel memory that can be memory mapped into userspace to allow speedy
harvesting.
This patch enables dirty ring for X86 only. However it should be
easily extended to other archs as well.
[1] https://patchwork.kernel.org/patch/10471409/
Signed-off-by: Lei Cao <lei.cao@stratus.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
Documentation/virt/kvm/api.txt | 118 ++++++++++++++++++++
arch/x86/include/asm/kvm_host.h | 3 +
arch/x86/include/uapi/asm/kvm.h | 1 +
arch/x86/kvm/Makefile | 3 +-
arch/x86/kvm/mmu/mmu.c | 6 ++
arch/x86/kvm/vmx/vmx.c | 7 ++
arch/x86/kvm/x86.c | 9 ++
include/linux/kvm_dirty_ring.h | 50 +++++++++
include/linux/kvm_host.h | 15 +++
include/trace/events/kvm.h | 78 ++++++++++++++
include/uapi/linux/kvm.h | 44 ++++++++
virt/kvm/dirty_ring.c | 176 ++++++++++++++++++++++++++++++
virt/kvm/kvm_main.c | 184 +++++++++++++++++++++++++++++++-
13 files changed, 692 insertions(+), 2 deletions(-)
create mode 100644 include/linux/kvm_dirty_ring.h
create mode 100644 virt/kvm/dirty_ring.c
diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt
index ebb37b34dcfc..558e719efdec 100644
--- a/Documentation/virt/kvm/api.txt
+++ b/Documentation/virt/kvm/api.txt
@@ -231,6 +231,7 @@ Based on their initialization different VMs may have different capabilities.
It is thus encouraged to use the vm ioctl to query for capabilities (available
with KVM_CAP_CHECK_EXTENSION_VM on the vm fd)
+
4.5 KVM_GET_VCPU_MMAP_SIZE
Capability: basic
@@ -243,6 +244,18 @@ The KVM_RUN ioctl (cf.) communicates with userspace via a shared
memory region. This ioctl returns the size of that region. See the
KVM_RUN documentation for details.
+Besides the size of the KVM_RUN communication region, other areas of
+the VCPU file descriptor can be mmap-ed, including:
+
+- if KVM_CAP_COALESCED_MMIO is available, a page at
+ KVM_COALESCED_MMIO_PAGE_OFFSET * PAGE_SIZE; for historical reasons,
+ this page is included in the result of KVM_GET_VCPU_MMAP_SIZE.
+ KVM_CAP_COALESCED_MMIO is not documented yet.
+
+- if KVM_CAP_DIRTY_LOG_RING is available, a number of pages at
+ KVM_DIRTY_LOG_PAGE_OFFSET * PAGE_SIZE. For more information on
+ KVM_CAP_DIRTY_LOG_RING, see section 8.3.
+
4.6 KVM_SET_MEMORY_REGION
@@ -5376,6 +5389,7 @@ CPU when the exception is taken. If this virtual SError is taken to EL1 using
AArch64, this value will be reported in the ISS field of ESR_ELx.
See KVM_CAP_VCPU_EVENTS for more details.
+
8.20 KVM_CAP_HYPERV_SEND_IPI
Architectures: x86
@@ -5383,6 +5397,7 @@ Architectures: x86
This capability indicates that KVM supports paravirtualized Hyper-V IPI send
hypercalls:
HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx.
+
8.21 KVM_CAP_HYPERV_DIRECT_TLBFLUSH
Architecture: x86
@@ -5396,3 +5411,106 @@ handling by KVM (as some KVM hypercall may be mistakenly treated as TLB
flush hypercalls by Hyper-V) so userspace should disable KVM identification
in CPUID and only exposes Hyper-V identification. In this case, guest
thinks it's running on Hyper-V and only use Hyper-V hypercalls.
+
+8.22 KVM_CAP_DIRTY_LOG_RING
+
+Architectures: x86
+Parameters: args[0] - size of the dirty log ring
+
+KVM is capable of tracking dirty memory using ring buffers that are
+mmaped into userspace; there is one dirty ring per vcpu.
+
+One dirty ring is defined as below internally:
+
+struct kvm_dirty_ring {
+ u32 dirty_index;
+ u32 reset_index;
+ u32 size;
+ u32 soft_limit;
+ struct kvm_dirty_gfn *dirty_gfns;
+ int index;
+};
+
+Dirty GFNs (Guest Frame Numbers) are stored in the dirty_gfns array.
+For each of the dirty entry it's defined as:
+
+struct kvm_dirty_gfn {
+ __u32 flags;
+ __u32 slot; /* as_id | slot_id */
+ __u64 offset;
+};
+
+Each GFN is a state machine itself. The state is embeded in the flags
+field, as defined in the uapi header:
+
+/*
+ * KVM dirty GFN flags, defined as:
+ *
+ * |---------------+---------------+--------------|
+ * | bit 1 (reset) | bit 0 (dirty) | Status |
+ * |---------------+---------------+--------------|
+ * | 0 | 0 | Invalid GFN |
+ * | 0 | 1 | Dirty GFN |
+ * | 1 | X | GFN to reset |
+ * |---------------+---------------+--------------|
+ *
+ * Lifecycle of a dirty GFN goes like:
+ *
+ * dirtied collected reset
+ * 00 -----------> 01 -------------> 1X -------+
+ * ^ |
+ * | |
+ * +------------------------------------------+
+ *
+ * The userspace program is only responsible for the 01->1X state
+ * conversion (to collect dirty bits). Also, it must not skip any
+ * dirty bits so that dirty bits are always collected in sequence.
+ */
+#define KVM_DIRTY_GFN_F_DIRTY BIT(0)
+#define KVM_DIRTY_GFN_F_RESET BIT(1)
+#define KVM_DIRTY_GFN_F_MASK 0x3
+
+Userspace calls KVM_ENABLE_CAP ioctl right after KVM_CREATE_VM ioctl
+to enable this capability for the new guest and set the size of the
+rings. It is only allowed before creating any vCPU, and the size of
+the ring must be a power of two. The larger the ring buffer, the less
+likely the ring is full and the VM is forced to exit to userspace. The
+optimal size depends on the workload, but it is recommended that it be
+at least 64 KiB (4096 entries).
+
+Just like for dirty page bitmaps, the buffer tracks writes to
+all user memory regions for which the KVM_MEM_LOG_DIRTY_PAGES flag was
+set in KVM_SET_USER_MEMORY_REGION. Once a memory region is registered
+with the flag set, userspace can start harvesting dirty pages from the
+ring buffer.
+
+To harvest the dirty pages, userspace accesses the mmaped ring buffer
+to read the dirty GFNs starting from zero. If the flags has the DIRTY
+bit set (at this stage the RESET bit must be cleared), then it means
+this GFN is a dirty GFN. The userspace should collect this GFN and
+mark the flags from state 01b to 1Xb (bit 0 will be ignored by KVM,
+but bit 1 must be set to show that this GFN is collected and waiting
+for a reset), and move on to the next GFN. The userspace should
+continue to do this until when the flags of a GFN has the DIRTY bit
+cleared, it means we've collected all the dirty GFNs we have for now.
+It's not a must that the userspace collects the all dirty GFNs in
+once. However it must collect the dirty GFNs in sequence, i.e., the
+userspace program cannot skip one dirty GFN to collect the one next to
+it.
+
+After processing one or more entries in the ring buffer, userspace
+calls the VM ioctl KVM_RESET_DIRTY_RINGS to notify the kernel about
+it, so that the kernel will reprotect those collected GFNs.
+Therefore, the ioctl must be called *before* reading the content of
+the dirty pages.
+
+The dirty ring interface has a major difference comparing to the
+KVM_GET_DIRTY_LOG interface in that, when reading the dirty ring from
+userspace it's still possible that the kernel has not yet flushed the
+hardware dirty buffers into the kernel buffer (the flushing was
+previously done by the KVM_GET_DIRTY_LOG ioctl). To achieve that, one
+needs to kick the vcpu out for a hardware buffer flush (vmexit) to
+make sure all the existing dirty gfns are flushed to the dirty rings.
+
+The dirty ring can gets full. When it happens, the KVM_RUN of the
+vcpu will return with exit reason KVM_EXIT_DIRTY_LOG_FULL.
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8fc46bbce57a..8a2419505b33 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1199,6 +1199,7 @@ struct kvm_x86_ops {
struct kvm_memory_slot *slot,
gfn_t offset, unsigned long mask);
int (*write_log_dirty)(struct kvm_vcpu *vcpu);
+ int (*cpu_dirty_log_size)(void);
/* pmu operations of sub-arch */
const struct kvm_pmu_ops *pmu_ops;
@@ -1688,4 +1689,6 @@ static inline int kvm_cpu_get_apicid(int mps_cpu)
#define GET_SMSTATE(type, buf, offset) \
(*(type *)((buf) + (offset) - 0x7e00))
+int kvm_cpu_dirty_log_size(void);
+
#endif /* _ASM_X86_KVM_HOST_H */
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 503d3f42da16..b59bf356c478 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -12,6 +12,7 @@
#define KVM_PIO_PAGE_OFFSET 1
#define KVM_COALESCED_MMIO_PAGE_OFFSET 2
+#define KVM_DIRTY_LOG_PAGE_OFFSET 64
#define DE_VECTOR 0
#define DB_VECTOR 1
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index b19ef421084d..0acee817adfb 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -5,7 +5,8 @@ ccflags-y += -Iarch/x86/kvm
KVM := ../../../virt/kvm
kvm-y += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o \
- $(KVM)/eventfd.o $(KVM)/irqchip.o $(KVM)/vfio.o
+ $(KVM)/eventfd.o $(KVM)/irqchip.o $(KVM)/vfio.o \
+ $(KVM)/dirty_ring.o
kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o
kvm-y += x86.o emulate.o i8259.o irq.o lapic.o \
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 84eeb61d06aa..92c250e26823 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1746,7 +1746,13 @@ int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu)
{
if (kvm_x86_ops->write_log_dirty)
return kvm_x86_ops->write_log_dirty(vcpu);
+ return 0;
+}
+int kvm_cpu_dirty_log_size(void)
+{
+ if (kvm_x86_ops->cpu_dirty_log_size)
+ return kvm_x86_ops->cpu_dirty_log_size();
return 0;
}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index a01f3bcef27a..c25eff0156a2 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7673,6 +7673,7 @@ static __init int hardware_setup(void)
kvm_x86_ops->slot_disable_log_dirty = NULL;
kvm_x86_ops->flush_log_dirty = NULL;
kvm_x86_ops->enable_log_dirty_pt_masked = NULL;
+ kvm_x86_ops->cpu_dirty_log_size = NULL;
}
if (!cpu_has_vmx_preemption_timer())
@@ -7745,6 +7746,11 @@ static bool vmx_check_apicv_inhibit_reasons(ulong bit)
return supported & BIT(bit);
}
+static int vmx_cpu_dirty_log_size(void)
+{
+ return enable_pml ? PML_ENTITY_NUM : 0;
+}
+
static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.cpu_has_kvm_support = cpu_has_kvm_support,
.disabled_by_bios = vmx_disabled_by_bios,
@@ -7868,6 +7874,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.flush_log_dirty = vmx_flush_log_dirty,
.enable_log_dirty_pt_masked = vmx_enable_log_dirty_pt_masked,
.write_log_dirty = vmx_write_pml_buffer,
+ .cpu_dirty_log_size = vmx_cpu_dirty_log_size,
.pre_block = vmx_pre_block,
.post_block = vmx_post_block,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 030435f1a033..5e6ceb9a9e73 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8132,6 +8132,15 @@ 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))) {
+ vcpu->run->exit_reason = KVM_EXIT_DIRTY_RING_FULL;
+ trace_kvm_dirty_ring_exit(vcpu);
+ r = 0;
+ goto out;
+ }
+
if (kvm_request_pending(vcpu)) {
if (kvm_check_request(KVM_REQ_GET_VMCS12_PAGES, vcpu)) {
if (unlikely(!kvm_x86_ops->get_vmcs12_pages(vcpu))) {
diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h
new file mode 100644
index 000000000000..9f1bf3704036
--- /dev/null
+++ b/include/linux/kvm_dirty_ring.h
@@ -0,0 +1,50 @@
+#ifndef KVM_DIRTY_RING_H
+#define KVM_DIRTY_RING_H
+
+/**
+ * kvm_dirty_ring: KVM internal dirty ring structure
+ *
+ * @dirty_index: free running counter that points to the next slot in
+ * dirty_ring->dirty_gfns, where a new dirty page should go
+ * @reset_index: free running counter that points to the next dirty page
+ * in dirty_ring->dirty_gfns for which dirty trap needs to
+ * be reenabled
+ * @size: size of the compact list, dirty_ring->dirty_gfns
+ * @soft_limit: when the number of dirty pages in the list reaches this
+ * limit, vcpu that owns this ring should exit to userspace
+ * to allow userspace to harvest all the dirty pages
+ * @dirty_gfns: the array to keep the dirty gfns
+ * @index: index of this dirty ring
+ */
+struct kvm_dirty_ring {
+ u32 dirty_index;
+ u32 reset_index;
+ u32 size;
+ u32 soft_limit;
+ struct kvm_dirty_gfn *dirty_gfns;
+ int index;
+};
+
+u32 kvm_dirty_ring_get_rsvd_entries(void);
+int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size);
+struct kvm_dirty_ring *kvm_dirty_ring_get(struct kvm *kvm);
+
+/*
+ * called with kvm->slots_lock held, returns the number of
+ * processed pages.
+ */
+int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring);
+
+/*
+ * returns =0: successfully pushed
+ * <0: unable to push, need to wait
+ */
+void kvm_dirty_ring_push(struct kvm_dirty_ring *ring, u32 slot, u64 offset);
+
+/* for use in vm_operations_struct */
+struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring, u32 offset);
+
+void kvm_dirty_ring_free(struct kvm_dirty_ring *ring);
+bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring);
+
+#endif /* KVM_DIRTY_RING_H */
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 62aad0a2707a..e9d6e96a47be 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -34,6 +34,7 @@
#include <linux/kvm_types.h>
#include <asm/kvm_host.h>
+#include <linux/kvm_dirty_ring.h>
#ifndef KVM_MAX_VCPU_ID
#define KVM_MAX_VCPU_ID KVM_MAX_VCPUS
@@ -319,6 +320,7 @@ struct kvm_vcpu {
bool ready;
struct kvm_vcpu_arch arch;
struct dentry *debugfs_dentry;
+ struct kvm_dirty_ring dirty_ring;
};
static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
@@ -500,6 +502,7 @@ struct kvm {
struct srcu_struct srcu;
struct srcu_struct irq_srcu;
pid_t userspace_pid;
+ u32 dirty_ring_size;
};
#define kvm_err(fmt, ...) \
@@ -828,6 +831,8 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
gfn_t gfn_offset,
unsigned long mask);
+void kvm_reset_dirty_gfn(struct kvm *kvm, u32 slot, u64 offset, u64 mask);
+
int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
struct kvm_dirty_log *log);
int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm,
@@ -1406,4 +1411,14 @@ int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn,
uintptr_t data, const char *name,
struct task_struct **thread_ptr);
+/*
+ * This defines how many reserved entries we want to keep before we
+ * kick the vcpu to the userspace to avoid dirty ring full. This
+ * value can be tuned to higher if e.g. PML is enabled on the host.
+ */
+#define KVM_DIRTY_RING_RSVD_ENTRIES 64
+
+/* Max number of entries allowed for each kvm dirty ring */
+#define KVM_DIRTY_RING_MAX_ENTRIES 65536
+
#endif
diff --git a/include/trace/events/kvm.h b/include/trace/events/kvm.h
index 2c735a3e6613..3d850997940c 100644
--- a/include/trace/events/kvm.h
+++ b/include/trace/events/kvm.h
@@ -399,6 +399,84 @@ TRACE_EVENT(kvm_halt_poll_ns,
#define trace_kvm_halt_poll_ns_shrink(vcpu_id, new, old) \
trace_kvm_halt_poll_ns(false, vcpu_id, new, old)
+TRACE_EVENT(kvm_dirty_ring_push,
+ TP_PROTO(struct kvm_dirty_ring *ring, u32 slot, u64 offset),
+ TP_ARGS(ring, slot, offset),
+
+ TP_STRUCT__entry(
+ __field(int, index)
+ __field(u32, dirty_index)
+ __field(u32, reset_index)
+ __field(u32, slot)
+ __field(u64, offset)
+ ),
+
+ TP_fast_assign(
+ __entry->index = ring->index;
+ __entry->dirty_index = ring->dirty_index;
+ __entry->reset_index = ring->reset_index;
+ __entry->slot = slot;
+ __entry->offset = offset;
+ ),
+
+ TP_printk("ring %d: dirty 0x%x reset 0x%x "
+ "slot %u offset 0x%llx (used %u)",
+ __entry->index, __entry->dirty_index,
+ __entry->reset_index, __entry->slot, __entry->offset,
+ __entry->dirty_index - __entry->reset_index)
+);
+
+TRACE_EVENT(kvm_dirty_ring_reset,
+ TP_PROTO(struct kvm_dirty_ring *ring),
+ TP_ARGS(ring),
+
+ TP_STRUCT__entry(
+ __field(int, index)
+ __field(u32, dirty_index)
+ __field(u32, reset_index)
+ ),
+
+ TP_fast_assign(
+ __entry->index = ring->index;
+ __entry->dirty_index = ring->dirty_index;
+ __entry->reset_index = ring->reset_index;
+ ),
+
+ TP_printk("ring %d: dirty 0x%x reset 0x%x (used %u)",
+ __entry->index, __entry->dirty_index, __entry->reset_index,
+ __entry->dirty_index - __entry->reset_index)
+);
+
+TRACE_EVENT(kvm_dirty_ring_waitqueue,
+ TP_PROTO(bool enter),
+ TP_ARGS(enter),
+
+ TP_STRUCT__entry(
+ __field(bool, enter)
+ ),
+
+ TP_fast_assign(
+ __entry->enter = enter;
+ ),
+
+ TP_printk("%s", __entry->enter ? "wait" : "awake")
+);
+
+TRACE_EVENT(kvm_dirty_ring_exit,
+ TP_PROTO(struct kvm_vcpu *vcpu),
+ TP_ARGS(vcpu),
+
+ TP_STRUCT__entry(
+ __field(int, vcpu_id)
+ ),
+
+ TP_fast_assign(
+ __entry->vcpu_id = vcpu->vcpu_id;
+ ),
+
+ TP_printk("vcpu %d", __entry->vcpu_id)
+);
+
#endif /* _TRACE_KVM_MAIN_H */
/* This part must be outside protection */
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index f0a16b4adbbd..5877d7fa88d1 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -236,6 +236,7 @@ struct kvm_hyperv_exit {
#define KVM_EXIT_IOAPIC_EOI 26
#define KVM_EXIT_HYPERV 27
#define KVM_EXIT_ARM_NISV 28
+#define KVM_EXIT_DIRTY_RING_FULL 29
/* For KVM_EXIT_INTERNAL_ERROR */
/* Emulate instruction failed. */
@@ -1009,6 +1010,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_PPC_GUEST_DEBUG_SSTEP 176
#define KVM_CAP_ARM_NISV_TO_USER 177
#define KVM_CAP_ARM_INJECT_EXT_DABT 178
+#define KVM_CAP_DIRTY_LOG_RING 179
#ifdef KVM_CAP_IRQ_ROUTING
@@ -1473,6 +1475,9 @@ struct kvm_enc_region {
/* Available with KVM_CAP_ARM_SVE */
#define KVM_ARM_VCPU_FINALIZE _IOW(KVMIO, 0xc2, int)
+/* Available with KVM_CAP_DIRTY_LOG_RING */
+#define KVM_RESET_DIRTY_RINGS _IO(KVMIO, 0xc3)
+
/* Secure Encrypted Virtualization command */
enum sev_cmd_id {
/* Guest initialization commands */
@@ -1623,4 +1628,43 @@ struct kvm_hyperv_eventfd {
#define KVM_HYPERV_CONN_ID_MASK 0x00ffffff
#define KVM_HYPERV_EVENTFD_DEASSIGN (1 << 0)
+/*
+ * KVM dirty GFN flags, defined as:
+ *
+ * |---------------+---------------+--------------|
+ * | bit 1 (reset) | bit 0 (dirty) | Status |
+ * |---------------+---------------+--------------|
+ * | 0 | 0 | Invalid GFN |
+ * | 0 | 1 | Dirty GFN |
+ * | 1 | X | GFN to reset |
+ * |---------------+---------------+--------------|
+ *
+ * Lifecycle of a dirty GFN goes like:
+ *
+ * dirtied collected reset
+ * 00 -----------> 01 -------------> 1X -------+
+ * ^ |
+ * | |
+ * +------------------------------------------+
+ *
+ * The userspace program is only responsible for the 01->1X state
+ * conversion (to collect dirty bits). Also, it must not skip any
+ * dirty bits so that dirty bits are always collected in sequence.
+ */
+#define KVM_DIRTY_GFN_F_DIRTY BIT(0)
+#define KVM_DIRTY_GFN_F_RESET BIT(1)
+#define KVM_DIRTY_GFN_F_MASK 0x3
+
+/*
+ * KVM dirty rings should be mapped at KVM_DIRTY_LOG_PAGE_OFFSET of
+ * per-vcpu mmaped regions as an array of struct kvm_dirty_gfn. The
+ * size of the gfn buffer is decided by the first argument when
+ * enabling KVM_CAP_DIRTY_LOG_RING.
+ */
+struct kvm_dirty_gfn {
+ __u32 flags;
+ __u32 slot;
+ __u64 offset;
+};
+
#endif /* __LINUX_KVM_H */
diff --git a/virt/kvm/dirty_ring.c b/virt/kvm/dirty_ring.c
new file mode 100644
index 000000000000..9c4145ad93b2
--- /dev/null
+++ b/virt/kvm/dirty_ring.c
@@ -0,0 +1,176 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * KVM dirty ring implementation
+ *
+ * Copyright 2019 Red Hat, Inc.
+ */
+#include <linux/kvm_host.h>
+#include <linux/kvm.h>
+#include <linux/vmalloc.h>
+#include <linux/kvm_dirty_ring.h>
+#include <trace/events/kvm.h>
+
+int __weak kvm_cpu_dirty_log_size(void)
+{
+ return 0;
+}
+
+u32 kvm_dirty_ring_get_rsvd_entries(void)
+{
+ return KVM_DIRTY_RING_RSVD_ENTRIES + kvm_cpu_dirty_log_size();
+}
+
+static u32 kvm_dirty_ring_used(struct kvm_dirty_ring *ring)
+{
+ return READ_ONCE(ring->dirty_index) - READ_ONCE(ring->reset_index);
+}
+
+bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring)
+{
+ return kvm_dirty_ring_used(ring) >= ring->soft_limit;
+}
+
+bool kvm_dirty_ring_full(struct kvm_dirty_ring *ring)
+{
+ return kvm_dirty_ring_used(ring) >= ring->size;
+}
+
+struct kvm_dirty_ring *kvm_dirty_ring_get(struct kvm *kvm)
+{
+ struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
+
+ WARN_ON_ONCE(vcpu->kvm != kvm);
+
+ return &vcpu->dirty_ring;
+}
+
+int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size)
+{
+ ring->dirty_gfns = vmalloc(size);
+ if (!ring->dirty_gfns)
+ return -ENOMEM;
+ memset(ring->dirty_gfns, 0, size);
+
+ ring->size = size / sizeof(struct kvm_dirty_gfn);
+ ring->soft_limit = ring->size - kvm_dirty_ring_get_rsvd_entries();
+ ring->dirty_index = 0;
+ ring->reset_index = 0;
+ ring->index = index;
+
+ return 0;
+}
+
+static inline void kvm_dirty_gfn_set_invalid(struct kvm_dirty_gfn *gfn)
+{
+ gfn->flags = 0;
+}
+
+static inline void kvm_dirty_gfn_set_dirtied(struct kvm_dirty_gfn *gfn)
+{
+ gfn->flags = KVM_DIRTY_GFN_F_DIRTY;
+}
+
+static inline bool kvm_dirty_gfn_invalid(struct kvm_dirty_gfn *gfn)
+{
+ return gfn->flags == 0;
+}
+
+static inline bool kvm_dirty_gfn_collected(struct kvm_dirty_gfn *gfn)
+{
+ return gfn->flags & KVM_DIRTY_GFN_F_RESET;
+}
+
+int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring)
+{
+ u32 cur_slot, next_slot;
+ u64 cur_offset, next_offset;
+ unsigned long mask;
+ int count = 0;
+ struct kvm_dirty_gfn *entry;
+ bool first_round = true;
+
+ /* This is only needed to make compilers happy */
+ cur_slot = cur_offset = mask = 0;
+
+ while (true) {
+ entry = &ring->dirty_gfns[ring->reset_index & (ring->size - 1)];
+
+ if (!kvm_dirty_gfn_collected(entry))
+ break;
+
+ next_slot = READ_ONCE(entry->slot);
+ next_offset = READ_ONCE(entry->offset);
+
+ /* Update the flags to reflect that this GFN is reset */
+ kvm_dirty_gfn_set_invalid(entry);
+
+ ring->reset_index++;
+ count++;
+ /*
+ * Try to coalesce the reset operations when the guest is
+ * scanning pages in the same slot.
+ */
+ if (!first_round && next_slot == cur_slot) {
+ s64 delta = next_offset - cur_offset;
+
+ if (delta >= 0 && delta < BITS_PER_LONG) {
+ mask |= 1ull << delta;
+ continue;
+ }
+
+ /* Backwards visit, careful about overflows! */
+ if (delta > -BITS_PER_LONG && delta < 0 &&
+ (mask << -delta >> -delta) == mask) {
+ cur_offset = next_offset;
+ mask = (mask << -delta) | 1;
+ continue;
+ }
+ }
+ kvm_reset_dirty_gfn(kvm, cur_slot, cur_offset, mask);
+ cur_slot = next_slot;
+ cur_offset = next_offset;
+ mask = 1;
+ first_round = false;
+ }
+
+ kvm_reset_dirty_gfn(kvm, cur_slot, cur_offset, mask);
+
+ trace_kvm_dirty_ring_reset(ring);
+
+ return count;
+}
+
+void kvm_dirty_ring_push(struct kvm_dirty_ring *ring, u32 slot, u64 offset)
+{
+ struct kvm_dirty_gfn *entry;
+
+ /* It should never get full */
+ WARN_ON_ONCE(kvm_dirty_ring_full(ring));
+
+ entry = &ring->dirty_gfns[ring->dirty_index & (ring->size - 1)];
+
+ /* It should always be an invalid entry to fill in */
+ WARN_ON_ONCE(!kvm_dirty_gfn_invalid(entry));
+
+ entry->slot = slot;
+ entry->offset = offset;
+ /*
+ * Make sure the data is filled in before we publish this to
+ * the userspace program. There's no paired kernel-side reader.
+ */
+ smp_wmb();
+ kvm_dirty_gfn_set_dirtied(entry);
+ ring->dirty_index++;
+ trace_kvm_dirty_ring_push(ring, slot, offset);
+}
+
+struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring, u32 offset)
+{
+ return vmalloc_to_page((void *)ring->dirty_gfns + offset * PAGE_SIZE);
+}
+
+void kvm_dirty_ring_free(struct kvm_dirty_ring *ring)
+{
+ vfree(ring->dirty_gfns);
+ ring->dirty_gfns = NULL;
+}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 5307f6e33587..b710cee7e897 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -64,12 +64,23 @@
#define CREATE_TRACE_POINTS
#include <trace/events/kvm.h>
+#include <linux/kvm_dirty_ring.h>
+
/* Worst case buffer size needed for holding an integer. */
#define ITOA_MAX_LEN 12
MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");
+/*
+ * Arch needs to define the macro after implementing the dirty ring
+ * feature. KVM_DIRTY_LOG_PAGE_OFFSET should be defined as the
+ * starting page offset of the dirty ring structures.
+ */
+#ifndef KVM_DIRTY_LOG_PAGE_OFFSET
+#define KVM_DIRTY_LOG_PAGE_OFFSET 0
+#endif
+
/* Architectures should define their poll value according to the halt latency */
unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT;
module_param(halt_poll_ns, uint, 0644);
@@ -337,6 +348,50 @@ void kvm_reload_remote_mmus(struct kvm *kvm)
kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
}
+#if (KVM_DIRTY_LOG_PAGE_OFFSET == 0)
+/*
+ * If KVM_DIRTY_LOG_PAGE_OFFSET not defined, kvm_dirty_ring.o should
+ * not be included as well, so define these nop functions for the arch.
+ */
+u32 kvm_dirty_ring_get_rsvd_entries(void)
+{
+ return 0;
+}
+
+int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size)
+{
+ return 0;
+}
+
+struct kvm_dirty_ring *kvm_dirty_ring_get(struct kvm *kvm)
+{
+ return NULL;
+}
+
+int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring)
+{
+ return 0;
+}
+
+void kvm_dirty_ring_push(struct kvm_dirty_ring *ring, u32 slot, u64 offset)
+{
+}
+
+struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring, u32 offset)
+{
+ return NULL;
+}
+
+void kvm_dirty_ring_free(struct kvm_dirty_ring *ring)
+{
+}
+
+bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring)
+{
+ return true;
+}
+#endif /* KVM_DIRTY_LOG_PAGE_OFFSET == 0 */
+
static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
{
mutex_init(&vcpu->mutex);
@@ -359,6 +414,7 @@ static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
{
+ kvm_dirty_ring_free(&vcpu->dirty_ring);
kvm_arch_vcpu_destroy(vcpu);
/*
@@ -2282,8 +2338,13 @@ static void mark_page_dirty_in_slot(struct kvm *kvm,
{
if (memslot && memslot->dirty_bitmap) {
unsigned long rel_gfn = gfn - memslot->base_gfn;
+ u32 slot = (memslot->as_id << 16) | memslot->id;
- set_bit_le(rel_gfn, memslot->dirty_bitmap);
+ if (kvm->dirty_ring_size)
+ kvm_dirty_ring_push(kvm_dirty_ring_get(kvm),
+ slot, rel_gfn);
+ else
+ set_bit_le(rel_gfn, memslot->dirty_bitmap);
}
}
@@ -2630,6 +2691,16 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode)
}
EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
+static bool kvm_page_in_dirty_ring(struct kvm *kvm, unsigned long pgoff)
+{
+ if (!KVM_DIRTY_LOG_PAGE_OFFSET)
+ return false;
+
+ return (pgoff >= KVM_DIRTY_LOG_PAGE_OFFSET) &&
+ (pgoff < KVM_DIRTY_LOG_PAGE_OFFSET +
+ kvm->dirty_ring_size / PAGE_SIZE);
+}
+
static vm_fault_t kvm_vcpu_fault(struct vm_fault *vmf)
{
struct kvm_vcpu *vcpu = vmf->vma->vm_file->private_data;
@@ -2645,6 +2716,10 @@ static vm_fault_t kvm_vcpu_fault(struct vm_fault *vmf)
else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
#endif
+ else if (kvm_page_in_dirty_ring(vcpu->kvm, vmf->pgoff))
+ page = kvm_dirty_ring_get_page(
+ &vcpu->dirty_ring,
+ vmf->pgoff - KVM_DIRTY_LOG_PAGE_OFFSET);
else
return kvm_arch_vcpu_fault(vcpu, vmf);
get_page(page);
@@ -2658,6 +2733,14 @@ static const struct vm_operations_struct kvm_vcpu_vm_ops = {
static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
{
+ struct kvm_vcpu *vcpu = file->private_data;
+ unsigned long pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+
+ if ((kvm_page_in_dirty_ring(vcpu->kvm, vma->vm_pgoff) ||
+ kvm_page_in_dirty_ring(vcpu->kvm, vma->vm_pgoff + pages - 1)) &&
+ ((vma->vm_flags & VM_EXEC) || !(vma->vm_flags & VM_SHARED)))
+ return -EINVAL;
+
vma->vm_ops = &kvm_vcpu_vm_ops;
return 0;
}
@@ -2751,6 +2834,13 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
if (r)
goto vcpu_free_run_page;
+ if (kvm->dirty_ring_size) {
+ r = kvm_dirty_ring_alloc(&vcpu->dirty_ring,
+ id, kvm->dirty_ring_size);
+ if (r)
+ goto arch_vcpu_destroy;
+ }
+
kvm_create_vcpu_debugfs(vcpu);
mutex_lock(&kvm->lock);
@@ -2786,6 +2876,8 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
unlock_vcpu_destroy:
mutex_unlock(&kvm->lock);
debugfs_remove_recursive(vcpu->debugfs_dentry);
+ kvm_dirty_ring_free(&vcpu->dirty_ring);
+arch_vcpu_destroy:
kvm_arch_vcpu_destroy(vcpu);
vcpu_free_run_page:
free_page((unsigned long)vcpu->run);
@@ -3256,12 +3348,97 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
#endif
case KVM_CAP_NR_MEMSLOTS:
return KVM_USER_MEM_SLOTS;
+ case KVM_CAP_DIRTY_LOG_RING:
+#ifdef CONFIG_X86
+ return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn);
+#else
+ return 0;
+#endif
default:
break;
}
return kvm_vm_ioctl_check_extension(kvm, arg);
}
+void kvm_reset_dirty_gfn(struct kvm *kvm, u32 slot, u64 offset, u64 mask)
+{
+ struct kvm_memory_slot *memslot;
+ int as_id, id;
+
+ as_id = slot >> 16;
+ id = (u16)slot;
+ if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
+ return;
+
+ memslot = id_to_memslot(__kvm_memslots(kvm, as_id), id);
+ if (offset >= memslot->npages)
+ return;
+
+ spin_lock(&kvm->mmu_lock);
+ kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot, offset, mask);
+ spin_unlock(&kvm->mmu_lock);
+}
+
+static int kvm_vm_ioctl_enable_dirty_log_ring(struct kvm *kvm, u32 size)
+{
+ int r;
+
+ if (!KVM_DIRTY_LOG_PAGE_OFFSET)
+ return -EINVAL;
+
+ /* the size should be power of 2 */
+ if (!size || (size & (size - 1)))
+ return -EINVAL;
+
+ /* Should be bigger to keep the reserved entries, or a page */
+ if (size < kvm_dirty_ring_get_rsvd_entries() *
+ sizeof(struct kvm_dirty_gfn) || size < PAGE_SIZE)
+ return -EINVAL;
+
+ if (size > KVM_DIRTY_RING_MAX_ENTRIES *
+ sizeof(struct kvm_dirty_gfn))
+ return -E2BIG;
+
+ /* We only allow it to set once */
+ if (kvm->dirty_ring_size)
+ return -EINVAL;
+
+ mutex_lock(&kvm->lock);
+
+ if (kvm->created_vcpus) {
+ /* We don't allow to change this value after vcpu created */
+ r = -EINVAL;
+ } else {
+ kvm->dirty_ring_size = size;
+ r = 0;
+ }
+
+ mutex_unlock(&kvm->lock);
+ return r;
+}
+
+static int kvm_vm_ioctl_reset_dirty_pages(struct kvm *kvm)
+{
+ int i;
+ struct kvm_vcpu *vcpu;
+ int cleared = 0;
+
+ if (!kvm->dirty_ring_size)
+ return -EINVAL;
+
+ mutex_lock(&kvm->slots_lock);
+
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ cleared += kvm_dirty_ring_reset(vcpu->kvm, &vcpu->dirty_ring);
+
+ mutex_unlock(&kvm->slots_lock);
+
+ if (cleared)
+ kvm_flush_remote_tlbs(kvm);
+
+ return cleared;
+}
+
int __attribute__((weak)) kvm_vm_ioctl_enable_cap(struct kvm *kvm,
struct kvm_enable_cap *cap)
{
@@ -3279,6 +3456,8 @@ static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm,
kvm->manual_dirty_log_protect = cap->args[0];
return 0;
#endif
+ case KVM_CAP_DIRTY_LOG_RING:
+ return kvm_vm_ioctl_enable_dirty_log_ring(kvm, cap->args[0]);
default:
return kvm_vm_ioctl_enable_cap(kvm, cap);
}
@@ -3466,6 +3645,9 @@ static long kvm_vm_ioctl(struct file *filp,
case KVM_CHECK_EXTENSION:
r = kvm_vm_ioctl_check_extension_generic(kvm, arg);
break;
+ case KVM_RESET_DIRTY_RINGS:
+ r = kvm_vm_ioctl_reset_dirty_pages(kvm);
+ break;
default:
r = kvm_arch_vm_ioctl(filp, ioctl, arg);
}
--
2.24.1
^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH 06/14] KVM: Make dirty ring exclusive to dirty bitmap log
2020-02-05 2:58 ` [PATCH 04/14] KVM: Pass in kvm pointer into mark_page_dirty_in_slot() Peter Xu
2020-02-05 2:58 ` [PATCH 05/14] KVM: X86: Implement ring-based dirty memory tracking Peter Xu
@ 2020-02-05 2:58 ` Peter Xu
2020-02-05 2:58 ` [PATCH 07/14] KVM: Don't allocate dirty bitmap if dirty ring is enabled Peter Xu
` (6 subsequent siblings)
8 siblings, 0 replies; 25+ messages in thread
From: Peter Xu @ 2020-02-05 2:58 UTC (permalink / raw)
To: kvm, linux-kernel
Cc: dinechin, sean.j.christopherson, pbonzini, jasowang, yan.y.zhao,
mst, peterx, kevin.tian, alex.williamson, dgilbert, vkuznets
There's no good reason to use both the dirty bitmap logging and the
new dirty ring buffer to track dirty bits. We should be able to even
support both of them at the same time, but it could complicate things
which could actually help little. Let's simply make it the rule
before we enable dirty ring on any arch, that we don't allow these two
interfaces to be used together.
The big world switch would be KVM_CAP_DIRTY_LOG_RING capability
enablement. That's where we'll switch from the default dirty logging
way to the dirty ring way. As long as kvm->dirty_ring_size is setup
correctly, we'll once and for all switch to the dirty ring buffer mode
for the current virtual machine.
Signed-off-by: Peter Xu <peterx@redhat.com>
---
Documentation/virt/kvm/api.txt | 7 +++++++
virt/kvm/kvm_main.c | 12 ++++++++++++
2 files changed, 19 insertions(+)
diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt
index 558e719efdec..bbdd68583cde 100644
--- a/Documentation/virt/kvm/api.txt
+++ b/Documentation/virt/kvm/api.txt
@@ -5514,3 +5514,10 @@ make sure all the existing dirty gfns are flushed to the dirty rings.
The dirty ring can gets full. When it happens, the KVM_RUN of the
vcpu will return with exit reason KVM_EXIT_DIRTY_LOG_FULL.
+
+NOTE: the KVM_CAP_DIRTY_LOG_RING capability and the new ioctl
+KVM_RESET_DIRTY_RINGS are exclusive to the existing KVM_GET_DIRTY_LOG
+interface. After enabling KVM_CAP_DIRTY_LOG_RING with an acceptable
+dirty ring size, the virtual machine will switch to the dirty ring
+tracking mode, and KVM_GET_DIRTY_LOG, KVM_CLEAR_DIRTY_LOG ioctls will
+stop working.
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index b710cee7e897..5a6f83b7270f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1243,6 +1243,10 @@ int kvm_get_dirty_log(struct kvm *kvm,
unsigned long n;
unsigned long any = 0;
+ /* Dirty ring tracking is exclusive to dirty log tracking */
+ if (kvm->dirty_ring_size)
+ return -EINVAL;
+
as_id = log->slot >> 16;
id = (u16)log->slot;
if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
@@ -1300,6 +1304,10 @@ int kvm_get_dirty_log_protect(struct kvm *kvm,
unsigned long *dirty_bitmap;
unsigned long *dirty_bitmap_buffer;
+ /* Dirty ring tracking is exclusive to dirty log tracking */
+ if (kvm->dirty_ring_size)
+ return -EINVAL;
+
as_id = log->slot >> 16;
id = (u16)log->slot;
if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
@@ -1371,6 +1379,10 @@ int kvm_clear_dirty_log_protect(struct kvm *kvm,
unsigned long *dirty_bitmap;
unsigned long *dirty_bitmap_buffer;
+ /* Dirty ring tracking is exclusive to dirty log tracking */
+ if (kvm->dirty_ring_size)
+ return -EINVAL;
+
as_id = log->slot >> 16;
id = (u16)log->slot;
if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
--
2.24.1
^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH 07/14] KVM: Don't allocate dirty bitmap if dirty ring is enabled
2020-02-05 2:58 ` [PATCH 04/14] KVM: Pass in kvm pointer into mark_page_dirty_in_slot() Peter Xu
2020-02-05 2:58 ` [PATCH 05/14] KVM: X86: Implement ring-based dirty memory tracking Peter Xu
2020-02-05 2:58 ` [PATCH 06/14] KVM: Make dirty ring exclusive to dirty bitmap log Peter Xu
@ 2020-02-05 2:58 ` Peter Xu
2020-02-05 2:58 ` [PATCH 08/14] KVM: selftests: Always clear dirty bitmap after iteration Peter Xu
` (5 subsequent siblings)
8 siblings, 0 replies; 25+ messages in thread
From: Peter Xu @ 2020-02-05 2:58 UTC (permalink / raw)
To: kvm, linux-kernel
Cc: dinechin, sean.j.christopherson, pbonzini, jasowang, yan.y.zhao,
mst, peterx, kevin.tian, alex.williamson, dgilbert, vkuznets
Because kvm dirty rings and kvm dirty log is used in an exclusive way,
Let's avoid creating the dirty_bitmap when kvm dirty ring is enabled.
At the meantime, since the dirty_bitmap will be conditionally created
now, we can't use it as a sign of "whether this memory slot enabled
dirty tracking". Change users like that to check against the kvm
memory slot flags.
Note that there still can be chances where the kvm memory slot got its
dirty_bitmap allocated, _if_ the memory slots are created before
enabling of the dirty rings and at the same time with the dirty
tracking capability enabled, they'll still with the dirty_bitmap.
However it should not hurt much (e.g., the bitmaps will always be
freed if they are there), and the real users normally won't trigger
this because dirty bit tracking flag should in most cases only be
applied to kvm slots only before migration starts, that should be far
latter than kvm initializes (VM starts).
Signed-off-by: Peter Xu <peterx@redhat.com>
---
arch/x86/kvm/mmu/mmu.c | 4 ++--
include/linux/kvm_host.h | 5 +++++
virt/kvm/kvm_main.c | 5 +++--
3 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 92c250e26823..039d20043ca3 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1273,8 +1273,8 @@ gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn,
slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
return NULL;
- if (no_dirty_log && slot->dirty_bitmap)
- return NULL;
+ if (no_dirty_log && kvm_slot_dirty_track_enabled(slot))
+ return false;
return slot;
}
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index e9d6e96a47be..a49e6846afe6 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -351,6 +351,11 @@ struct kvm_memory_slot {
u8 as_id;
};
+static inline bool kvm_slot_dirty_track_enabled(struct kvm_memory_slot *slot)
+{
+ return slot->flags & KVM_MEM_LOG_DIRTY_PAGES;
+}
+
static inline unsigned long kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot)
{
return ALIGN(memslot->npages, BITS_PER_LONG) / 8;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 5a6f83b7270f..72b45f491692 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1152,7 +1152,8 @@ int __kvm_set_memory_region(struct kvm *kvm,
}
/* Allocate page dirty bitmap if needed */
- if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
+ if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap &&
+ !kvm->dirty_ring_size) {
if (kvm_create_dirty_bitmap(&new) < 0)
goto out_free;
}
@@ -2348,7 +2349,7 @@ static void mark_page_dirty_in_slot(struct kvm *kvm,
struct kvm_memory_slot *memslot,
gfn_t gfn)
{
- if (memslot && memslot->dirty_bitmap) {
+ if (memslot && kvm_slot_dirty_track_enabled(memslot)) {
unsigned long rel_gfn = gfn - memslot->base_gfn;
u32 slot = (memslot->as_id << 16) | memslot->id;
--
2.24.1
^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH 08/14] KVM: selftests: Always clear dirty bitmap after iteration
2020-02-05 2:58 ` [PATCH 04/14] KVM: Pass in kvm pointer into mark_page_dirty_in_slot() Peter Xu
` (2 preceding siblings ...)
2020-02-05 2:58 ` [PATCH 07/14] KVM: Don't allocate dirty bitmap if dirty ring is enabled Peter Xu
@ 2020-02-05 2:58 ` Peter Xu
2020-02-05 2:58 ` [PATCH 09/14] KVM: selftests: Sync uapi/linux/kvm.h to tools/ Peter Xu
` (4 subsequent siblings)
8 siblings, 0 replies; 25+ messages in thread
From: Peter Xu @ 2020-02-05 2:58 UTC (permalink / raw)
To: kvm, linux-kernel
Cc: dinechin, sean.j.christopherson, pbonzini, jasowang, yan.y.zhao,
mst, peterx, kevin.tian, alex.williamson, dgilbert, vkuznets
We don't clear the dirty bitmap before because KVM_GET_DIRTY_LOG will
clear it for us before copying the dirty log onto it. However we'd
still better to clear it explicitly instead of assuming the kernel
will always do it for us.
More importantly, in the upcoming dirty ring tests we'll start to
fetch dirty pages from a ring buffer, so no one is going to clear the
dirty bitmap for us.
Signed-off-by: Peter Xu <peterx@redhat.com>
---
tools/testing/selftests/kvm/dirty_log_test.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index 5614222a6628..3c0ffd34b3b0 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -197,7 +197,7 @@ static void vm_dirty_log_verify(unsigned long *bmap)
page);
}
- if (test_bit_le(page, bmap)) {
+ if (test_and_clear_bit_le(page, bmap)) {
host_dirty_count++;
/*
* If the bit is set, the value written onto
--
2.24.1
^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH 09/14] KVM: selftests: Sync uapi/linux/kvm.h to tools/
2020-02-05 2:58 ` [PATCH 04/14] KVM: Pass in kvm pointer into mark_page_dirty_in_slot() Peter Xu
` (3 preceding siblings ...)
2020-02-05 2:58 ` [PATCH 08/14] KVM: selftests: Always clear dirty bitmap after iteration Peter Xu
@ 2020-02-05 2:58 ` Peter Xu
2020-02-05 2:58 ` [PATCH 10/14] KVM: selftests: Use a single binary for dirty/clear log test Peter Xu
` (3 subsequent siblings)
8 siblings, 0 replies; 25+ messages in thread
From: Peter Xu @ 2020-02-05 2:58 UTC (permalink / raw)
To: kvm, linux-kernel
Cc: dinechin, sean.j.christopherson, pbonzini, jasowang, yan.y.zhao,
mst, peterx, kevin.tian, alex.williamson, dgilbert, vkuznets
This will be needed to extend the kvm selftest program.
Signed-off-by: Peter Xu <peterx@redhat.com>
---
tools/include/uapi/linux/kvm.h | 44 ++++++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)
diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
index f0a16b4adbbd..5877d7fa88d1 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -236,6 +236,7 @@ struct kvm_hyperv_exit {
#define KVM_EXIT_IOAPIC_EOI 26
#define KVM_EXIT_HYPERV 27
#define KVM_EXIT_ARM_NISV 28
+#define KVM_EXIT_DIRTY_RING_FULL 29
/* For KVM_EXIT_INTERNAL_ERROR */
/* Emulate instruction failed. */
@@ -1009,6 +1010,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_PPC_GUEST_DEBUG_SSTEP 176
#define KVM_CAP_ARM_NISV_TO_USER 177
#define KVM_CAP_ARM_INJECT_EXT_DABT 178
+#define KVM_CAP_DIRTY_LOG_RING 179
#ifdef KVM_CAP_IRQ_ROUTING
@@ -1473,6 +1475,9 @@ struct kvm_enc_region {
/* Available with KVM_CAP_ARM_SVE */
#define KVM_ARM_VCPU_FINALIZE _IOW(KVMIO, 0xc2, int)
+/* Available with KVM_CAP_DIRTY_LOG_RING */
+#define KVM_RESET_DIRTY_RINGS _IO(KVMIO, 0xc3)
+
/* Secure Encrypted Virtualization command */
enum sev_cmd_id {
/* Guest initialization commands */
@@ -1623,4 +1628,43 @@ struct kvm_hyperv_eventfd {
#define KVM_HYPERV_CONN_ID_MASK 0x00ffffff
#define KVM_HYPERV_EVENTFD_DEASSIGN (1 << 0)
+/*
+ * KVM dirty GFN flags, defined as:
+ *
+ * |---------------+---------------+--------------|
+ * | bit 1 (reset) | bit 0 (dirty) | Status |
+ * |---------------+---------------+--------------|
+ * | 0 | 0 | Invalid GFN |
+ * | 0 | 1 | Dirty GFN |
+ * | 1 | X | GFN to reset |
+ * |---------------+---------------+--------------|
+ *
+ * Lifecycle of a dirty GFN goes like:
+ *
+ * dirtied collected reset
+ * 00 -----------> 01 -------------> 1X -------+
+ * ^ |
+ * | |
+ * +------------------------------------------+
+ *
+ * The userspace program is only responsible for the 01->1X state
+ * conversion (to collect dirty bits). Also, it must not skip any
+ * dirty bits so that dirty bits are always collected in sequence.
+ */
+#define KVM_DIRTY_GFN_F_DIRTY BIT(0)
+#define KVM_DIRTY_GFN_F_RESET BIT(1)
+#define KVM_DIRTY_GFN_F_MASK 0x3
+
+/*
+ * KVM dirty rings should be mapped at KVM_DIRTY_LOG_PAGE_OFFSET of
+ * per-vcpu mmaped regions as an array of struct kvm_dirty_gfn. The
+ * size of the gfn buffer is decided by the first argument when
+ * enabling KVM_CAP_DIRTY_LOG_RING.
+ */
+struct kvm_dirty_gfn {
+ __u32 flags;
+ __u32 slot;
+ __u64 offset;
+};
+
#endif /* __LINUX_KVM_H */
--
2.24.1
^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH 10/14] KVM: selftests: Use a single binary for dirty/clear log test
2020-02-05 2:58 ` [PATCH 04/14] KVM: Pass in kvm pointer into mark_page_dirty_in_slot() Peter Xu
` (4 preceding siblings ...)
2020-02-05 2:58 ` [PATCH 09/14] KVM: selftests: Sync uapi/linux/kvm.h to tools/ Peter Xu
@ 2020-02-05 2:58 ` Peter Xu
2020-02-05 9:28 ` Andrew Jones
2020-02-05 2:58 ` [PATCH 11/14] KVM: selftests: Introduce after_vcpu_run hook for dirty " Peter Xu
` (2 subsequent siblings)
8 siblings, 1 reply; 25+ messages in thread
From: Peter Xu @ 2020-02-05 2:58 UTC (permalink / raw)
To: kvm, linux-kernel
Cc: dinechin, sean.j.christopherson, pbonzini, jasowang, yan.y.zhao,
mst, peterx, kevin.tian, alex.williamson, dgilbert, vkuznets
Remove the clear_dirty_log test, instead merge it into the existing
dirty_log_test. It should be cleaner to use this single binary to do
both tests, also it's a preparation for the upcoming dirty ring test.
The default test will still be the dirty_log test. To run the clear
dirty log test, we need to specify "-M clear-log".
Signed-off-by: Peter Xu <peterx@redhat.com>
---
tools/testing/selftests/kvm/Makefile | 2 -
.../selftests/kvm/clear_dirty_log_test.c | 2 -
tools/testing/selftests/kvm/dirty_log_test.c | 131 +++++++++++++++---
3 files changed, 110 insertions(+), 25 deletions(-)
delete mode 100644 tools/testing/selftests/kvm/clear_dirty_log_test.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 89bf05d4c2f3..9744966a48c5 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -26,12 +26,10 @@ TEST_GEN_PROGS_x86_64 += x86_64/vmx_dirty_log_test
TEST_GEN_PROGS_x86_64 += x86_64/vmx_set_nested_state_test
TEST_GEN_PROGS_x86_64 += x86_64/vmx_tsc_adjust_test
TEST_GEN_PROGS_x86_64 += x86_64/xss_msr_test
-TEST_GEN_PROGS_x86_64 += clear_dirty_log_test
TEST_GEN_PROGS_x86_64 += dirty_log_test
TEST_GEN_PROGS_x86_64 += demand_paging_test
TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus
-TEST_GEN_PROGS_aarch64 += clear_dirty_log_test
TEST_GEN_PROGS_aarch64 += dirty_log_test
TEST_GEN_PROGS_aarch64 += demand_paging_test
TEST_GEN_PROGS_aarch64 += kvm_create_max_vcpus
diff --git a/tools/testing/selftests/kvm/clear_dirty_log_test.c b/tools/testing/selftests/kvm/clear_dirty_log_test.c
deleted file mode 100644
index 749336937d37..000000000000
--- a/tools/testing/selftests/kvm/clear_dirty_log_test.c
+++ /dev/null
@@ -1,2 +0,0 @@
-#define USE_CLEAR_DIRTY_LOG
-#include "dirty_log_test.c"
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index 3c0ffd34b3b0..a8ae8c0042a8 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -128,6 +128,66 @@ static uint64_t host_dirty_count;
static uint64_t host_clear_count;
static uint64_t host_track_next_count;
+enum log_mode_t {
+ /* Only use KVM_GET_DIRTY_LOG for logging */
+ LOG_MODE_DIRTY_LOG = 0,
+
+ /* Use both KVM_[GET|CLEAR]_DIRTY_LOG for logging */
+ LOG_MODE_CLERA_LOG = 1,
+
+ LOG_MODE_NUM,
+};
+
+/* Mode of logging. Default is LOG_MODE_DIRTY_LOG */
+static enum log_mode_t host_log_mode;
+
+static void clear_log_create_vm_done(struct kvm_vm *vm)
+{
+ struct kvm_enable_cap cap = {};
+
+ if (!kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2)) {
+ fprintf(stderr, "KVM_CLEAR_DIRTY_LOG not available, skipping tests\n");
+ exit(KSFT_SKIP);
+ }
+
+ cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
+ cap.args[0] = 1;
+ vm_enable_cap(vm, &cap);
+}
+
+static void dirty_log_collect_dirty_pages(struct kvm_vm *vm, int slot,
+ void *bitmap, uint32_t num_pages)
+{
+ kvm_vm_get_dirty_log(vm, slot, bitmap);
+}
+
+static void clear_log_collect_dirty_pages(struct kvm_vm *vm, int slot,
+ void *bitmap, uint32_t num_pages)
+{
+ kvm_vm_get_dirty_log(vm, slot, bitmap);
+ kvm_vm_clear_dirty_log(vm, slot, bitmap, 0, num_pages);
+}
+
+struct log_mode {
+ const char *name;
+ /* Hook when the vm creation is done (before vcpu creation) */
+ void (*create_vm_done)(struct kvm_vm *vm);
+ /* Hook to collect the dirty pages into the bitmap provided */
+ void (*collect_dirty_pages) (struct kvm_vm *vm, int slot,
+ void *bitmap, uint32_t num_pages);
+} log_modes[LOG_MODE_NUM] = {
+ {
+ .name = "dirty-log",
+ .create_vm_done = NULL,
+ .collect_dirty_pages = dirty_log_collect_dirty_pages,
+ },
+ {
+ .name = "clear-log",
+ .create_vm_done = clear_log_create_vm_done,
+ .collect_dirty_pages = clear_log_collect_dirty_pages,
+ },
+};
+
/*
* We use this bitmap to track some pages that should have its dirty
* bit set in the _next_ iteration. For example, if we detected the
@@ -137,6 +197,33 @@ static uint64_t host_track_next_count;
*/
static unsigned long *host_bmap_track;
+static void log_modes_dump(void)
+{
+ int i;
+
+ for (i = 0; i < LOG_MODE_NUM; i++)
+ printf("%s, ", log_modes[i].name);
+ puts("\b\b \b\b");
+}
+
+static void log_mode_create_vm_done(struct kvm_vm *vm)
+{
+ struct log_mode *mode = &log_modes[host_log_mode];
+
+ if (mode->create_vm_done)
+ mode->create_vm_done(vm);
+}
+
+static void log_mode_collect_dirty_pages(struct kvm_vm *vm, int slot,
+ void *bitmap, uint32_t num_pages)
+{
+ struct log_mode *mode = &log_modes[host_log_mode];
+
+ TEST_ASSERT(mode->collect_dirty_pages != NULL,
+ "collect_dirty_pages() is required for any log mode!");
+ mode->collect_dirty_pages(vm, slot, bitmap, num_pages);
+}
+
static void generate_random_array(uint64_t *guest_array, uint64_t size)
{
uint64_t i;
@@ -257,6 +344,7 @@ static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,
#ifdef __x86_64__
vm_create_irqchip(vm);
#endif
+ log_mode_create_vm_done(vm);
vm_vcpu_add_default(vm, vcpuid, guest_code);
return vm;
}
@@ -316,14 +404,6 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations,
bmap = bitmap_alloc(host_num_pages);
host_bmap_track = bitmap_alloc(host_num_pages);
-#ifdef USE_CLEAR_DIRTY_LOG
- struct kvm_enable_cap cap = {};
-
- cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
- cap.args[0] = 1;
- vm_enable_cap(vm, &cap);
-#endif
-
/* Add an extra memory slot for testing dirty logging */
vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
guest_test_phys_mem,
@@ -364,11 +444,8 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations,
while (iteration < iterations) {
/* Give the vcpu thread some time to dirty some pages */
usleep(interval * 1000);
- kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
-#ifdef USE_CLEAR_DIRTY_LOG
- kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0,
- host_num_pages);
-#endif
+ log_mode_collect_dirty_pages(vm, TEST_MEM_SLOT_INDEX,
+ bmap, host_num_pages);
vm_dirty_log_verify(bmap);
iteration++;
sync_global_to_guest(vm, iteration);
@@ -413,6 +490,9 @@ static void help(char *name)
TEST_HOST_LOOP_INTERVAL);
printf(" -p: specify guest physical test memory offset\n"
" Warning: a low offset can conflict with the loaded test code.\n");
+ printf(" -M: specify the host logging mode "
+ "(default: log-dirty). Supported modes: \n\t");
+ log_modes_dump();
printf(" -m: specify the guest mode ID to test "
"(default: test all supported modes)\n"
" This option may be used multiple times.\n"
@@ -437,13 +517,6 @@ int main(int argc, char *argv[])
unsigned int host_ipa_limit;
#endif
-#ifdef USE_CLEAR_DIRTY_LOG
- if (!kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2)) {
- fprintf(stderr, "KVM_CLEAR_DIRTY_LOG not available, skipping tests\n");
- exit(KSFT_SKIP);
- }
-#endif
-
#ifdef __x86_64__
vm_guest_mode_params_init(VM_MODE_PXXV48_4K, true, true);
#endif
@@ -463,7 +536,7 @@ int main(int argc, char *argv[])
vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true);
#endif
- while ((opt = getopt(argc, argv, "hi:I:p:m:")) != -1) {
+ while ((opt = getopt(argc, argv, "hi:I:p:m:M:")) != -1) {
switch (opt) {
case 'i':
iterations = strtol(optarg, NULL, 10);
@@ -485,6 +558,22 @@ int main(int argc, char *argv[])
"Guest mode ID %d too big", mode);
vm_guest_mode_params[mode].enabled = true;
break;
+ case 'M':
+ for (i = 0; i < LOG_MODE_NUM; i++) {
+ if (!strcmp(optarg, log_modes[i].name)) {
+ DEBUG("Setting log mode to: '%s'\n",
+ optarg);
+ host_log_mode = i;
+ break;
+ }
+ }
+ if (i == LOG_MODE_NUM) {
+ printf("Log mode '%s' is invalid. "
+ "Please choose from: ", optarg);
+ log_modes_dump();
+ exit(-1);
+ }
+ break;
case 'h':
default:
help(argv[0]);
--
2.24.1
^ permalink raw reply related [flat|nested] 25+ messages in thread
* Re: [PATCH 10/14] KVM: selftests: Use a single binary for dirty/clear log test
2020-02-05 2:58 ` [PATCH 10/14] KVM: selftests: Use a single binary for dirty/clear log test Peter Xu
@ 2020-02-05 9:28 ` Andrew Jones
2020-02-05 15:46 ` Peter Xu
0 siblings, 1 reply; 25+ messages in thread
From: Andrew Jones @ 2020-02-05 9:28 UTC (permalink / raw)
To: Peter Xu
Cc: kvm, linux-kernel, dinechin, sean.j.christopherson, pbonzini,
jasowang, yan.y.zhao, mst, kevin.tian, alex.williamson, dgilbert,
vkuznets
On Tue, Feb 04, 2020 at 09:58:38PM -0500, Peter Xu wrote:
> Remove the clear_dirty_log test, instead merge it into the existing
> dirty_log_test. It should be cleaner to use this single binary to do
> both tests, also it's a preparation for the upcoming dirty ring test.
>
> The default test will still be the dirty_log test. To run the clear
> dirty log test, we need to specify "-M clear-log".
How about keeping most of these changes, which nicely clean up the
#ifdefs, but also keeping the separate test, which I think is the
preferred way to organize and execute selftests. We can use argv[0]
to determine which path to take rather than a command line parameter.
Thanks,
drew
^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH 10/14] KVM: selftests: Use a single binary for dirty/clear log test
2020-02-05 9:28 ` Andrew Jones
@ 2020-02-05 15:46 ` Peter Xu
2020-02-05 17:11 ` Andrew Jones
0 siblings, 1 reply; 25+ messages in thread
From: Peter Xu @ 2020-02-05 15:46 UTC (permalink / raw)
To: Andrew Jones
Cc: kvm, linux-kernel, dinechin, sean.j.christopherson, pbonzini,
jasowang, yan.y.zhao, mst, kevin.tian, alex.williamson, dgilbert,
vkuznets
On Wed, Feb 05, 2020 at 10:28:52AM +0100, Andrew Jones wrote:
> On Tue, Feb 04, 2020 at 09:58:38PM -0500, Peter Xu wrote:
> > Remove the clear_dirty_log test, instead merge it into the existing
> > dirty_log_test. It should be cleaner to use this single binary to do
> > both tests, also it's a preparation for the upcoming dirty ring test.
> >
> > The default test will still be the dirty_log test. To run the clear
> > dirty log test, we need to specify "-M clear-log".
>
> How about keeping most of these changes, which nicely clean up the
> #ifdefs, but also keeping the separate test, which I think is the
> preferred way to organize and execute selftests. We can use argv[0]
> to determine which path to take rather than a command line parameter.
Hi, Drew,
How about we just create a few selftest links that points to the same
test binary in Makefile? I'm fine with compiling it for mulitple
binaries too, just in case the makefile trick could be even easier.
Thanks,
--
Peter Xu
^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH 10/14] KVM: selftests: Use a single binary for dirty/clear log test
2020-02-05 15:46 ` Peter Xu
@ 2020-02-05 17:11 ` Andrew Jones
2020-02-05 17:39 ` Peter Xu
0 siblings, 1 reply; 25+ messages in thread
From: Andrew Jones @ 2020-02-05 17:11 UTC (permalink / raw)
To: Peter Xu
Cc: kvm, linux-kernel, dinechin, sean.j.christopherson, pbonzini,
jasowang, yan.y.zhao, mst, kevin.tian, alex.williamson, dgilbert,
vkuznets
On Wed, Feb 05, 2020 at 10:46:17AM -0500, Peter Xu wrote:
> On Wed, Feb 05, 2020 at 10:28:52AM +0100, Andrew Jones wrote:
> > On Tue, Feb 04, 2020 at 09:58:38PM -0500, Peter Xu wrote:
> > > Remove the clear_dirty_log test, instead merge it into the existing
> > > dirty_log_test. It should be cleaner to use this single binary to do
> > > both tests, also it's a preparation for the upcoming dirty ring test.
> > >
> > > The default test will still be the dirty_log test. To run the clear
> > > dirty log test, we need to specify "-M clear-log".
> >
> > How about keeping most of these changes, which nicely clean up the
> > #ifdefs, but also keeping the separate test, which I think is the
> > preferred way to organize and execute selftests. We can use argv[0]
> > to determine which path to take rather than a command line parameter.
>
> Hi, Drew,
>
> How about we just create a few selftest links that points to the same
> test binary in Makefile? I'm fine with compiling it for mulitple
> binaries too, just in case the makefile trick could be even easier.
I think I prefer the binaries. That way they can be selectively moved
and run elsewhere, i.e. each test is a standalone test.
Thanks,
drew
^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH 10/14] KVM: selftests: Use a single binary for dirty/clear log test
2020-02-05 17:11 ` Andrew Jones
@ 2020-02-05 17:39 ` Peter Xu
2020-02-06 22:40 ` Peter Xu
0 siblings, 1 reply; 25+ messages in thread
From: Peter Xu @ 2020-02-05 17:39 UTC (permalink / raw)
To: Andrew Jones
Cc: kvm, linux-kernel, dinechin, sean.j.christopherson, pbonzini,
jasowang, yan.y.zhao, mst, kevin.tian, alex.williamson, dgilbert,
vkuznets
On Wed, Feb 05, 2020 at 06:11:09PM +0100, Andrew Jones wrote:
> On Wed, Feb 05, 2020 at 10:46:17AM -0500, Peter Xu wrote:
> > On Wed, Feb 05, 2020 at 10:28:52AM +0100, Andrew Jones wrote:
> > > On Tue, Feb 04, 2020 at 09:58:38PM -0500, Peter Xu wrote:
> > > > Remove the clear_dirty_log test, instead merge it into the existing
> > > > dirty_log_test. It should be cleaner to use this single binary to do
> > > > both tests, also it's a preparation for the upcoming dirty ring test.
> > > >
> > > > The default test will still be the dirty_log test. To run the clear
> > > > dirty log test, we need to specify "-M clear-log".
> > >
> > > How about keeping most of these changes, which nicely clean up the
> > > #ifdefs, but also keeping the separate test, which I think is the
> > > preferred way to organize and execute selftests. We can use argv[0]
> > > to determine which path to take rather than a command line parameter.
> >
> > Hi, Drew,
> >
> > How about we just create a few selftest links that points to the same
> > test binary in Makefile? I'm fine with compiling it for mulitple
> > binaries too, just in case the makefile trick could be even easier.
>
> I think I prefer the binaries. That way they can be selectively moved
> and run elsewhere, i.e. each test is a standalone test.
Sure, will do.
--
Peter Xu
^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH 10/14] KVM: selftests: Use a single binary for dirty/clear log test
2020-02-05 17:39 ` Peter Xu
@ 2020-02-06 22:40 ` Peter Xu
2020-02-07 8:31 ` Andrew Jones
0 siblings, 1 reply; 25+ messages in thread
From: Peter Xu @ 2020-02-06 22:40 UTC (permalink / raw)
To: Andrew Jones
Cc: kvm, linux-kernel, dinechin, sean.j.christopherson, pbonzini,
jasowang, yan.y.zhao, mst, kevin.tian, alex.williamson, dgilbert,
vkuznets
On Wed, Feb 05, 2020 at 12:39:39PM -0500, Peter Xu wrote:
> On Wed, Feb 05, 2020 at 06:11:09PM +0100, Andrew Jones wrote:
> > On Wed, Feb 05, 2020 at 10:46:17AM -0500, Peter Xu wrote:
> > > On Wed, Feb 05, 2020 at 10:28:52AM +0100, Andrew Jones wrote:
> > > > On Tue, Feb 04, 2020 at 09:58:38PM -0500, Peter Xu wrote:
> > > > > Remove the clear_dirty_log test, instead merge it into the existing
> > > > > dirty_log_test. It should be cleaner to use this single binary to do
> > > > > both tests, also it's a preparation for the upcoming dirty ring test.
> > > > >
> > > > > The default test will still be the dirty_log test. To run the clear
> > > > > dirty log test, we need to specify "-M clear-log".
> > > >
> > > > How about keeping most of these changes, which nicely clean up the
> > > > #ifdefs, but also keeping the separate test, which I think is the
> > > > preferred way to organize and execute selftests. We can use argv[0]
> > > > to determine which path to take rather than a command line parameter.
> > >
> > > Hi, Drew,
> > >
> > > How about we just create a few selftest links that points to the same
> > > test binary in Makefile? I'm fine with compiling it for mulitple
> > > binaries too, just in case the makefile trick could be even easier.
> >
> > I think I prefer the binaries. That way they can be selectively moved
> > and run elsewhere, i.e. each test is a standalone test.
>
> Sure, will do.
Or... Shall we still keep one binary, but by default run all the
supported logging mode in sequence in a single dirty_log_test? Say,
run "./dirty_log_test" will run all supported tests one by one; run
"./dirty_log_test -M LOG_MODE" will only run specific mode.
With this patch it's fairly easy to achieve this too.
--
Peter Xu
^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH 10/14] KVM: selftests: Use a single binary for dirty/clear log test
2020-02-06 22:40 ` Peter Xu
@ 2020-02-07 8:31 ` Andrew Jones
0 siblings, 0 replies; 25+ messages in thread
From: Andrew Jones @ 2020-02-07 8:31 UTC (permalink / raw)
To: Peter Xu
Cc: kvm, linux-kernel, dinechin, sean.j.christopherson, pbonzini,
jasowang, yan.y.zhao, mst, kevin.tian, alex.williamson, dgilbert,
vkuznets
On Thu, Feb 06, 2020 at 05:40:42PM -0500, Peter Xu wrote:
> On Wed, Feb 05, 2020 at 12:39:39PM -0500, Peter Xu wrote:
> > On Wed, Feb 05, 2020 at 06:11:09PM +0100, Andrew Jones wrote:
> > > On Wed, Feb 05, 2020 at 10:46:17AM -0500, Peter Xu wrote:
> > > > On Wed, Feb 05, 2020 at 10:28:52AM +0100, Andrew Jones wrote:
> > > > > On Tue, Feb 04, 2020 at 09:58:38PM -0500, Peter Xu wrote:
> > > > > > Remove the clear_dirty_log test, instead merge it into the existing
> > > > > > dirty_log_test. It should be cleaner to use this single binary to do
> > > > > > both tests, also it's a preparation for the upcoming dirty ring test.
> > > > > >
> > > > > > The default test will still be the dirty_log test. To run the clear
> > > > > > dirty log test, we need to specify "-M clear-log".
> > > > >
> > > > > How about keeping most of these changes, which nicely clean up the
> > > > > #ifdefs, but also keeping the separate test, which I think is the
> > > > > preferred way to organize and execute selftests. We can use argv[0]
> > > > > to determine which path to take rather than a command line parameter.
> > > >
> > > > Hi, Drew,
> > > >
> > > > How about we just create a few selftest links that points to the same
> > > > test binary in Makefile? I'm fine with compiling it for mulitple
> > > > binaries too, just in case the makefile trick could be even easier.
> > >
> > > I think I prefer the binaries. That way they can be selectively moved
> > > and run elsewhere, i.e. each test is a standalone test.
> >
> > Sure, will do.
>
> Or... Shall we still keep one binary, but by default run all the
> supported logging mode in sequence in a single dirty_log_test? Say,
> run "./dirty_log_test" will run all supported tests one by one; run
> "./dirty_log_test -M LOG_MODE" will only run specific mode.
>
> With this patch it's fairly easy to achieve this too.
>
Works for me.
Thanks,
drew
^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH 11/14] KVM: selftests: Introduce after_vcpu_run hook for dirty log test
2020-02-05 2:58 ` [PATCH 04/14] KVM: Pass in kvm pointer into mark_page_dirty_in_slot() Peter Xu
` (5 preceding siblings ...)
2020-02-05 2:58 ` [PATCH 10/14] KVM: selftests: Use a single binary for dirty/clear log test Peter Xu
@ 2020-02-05 2:58 ` Peter Xu
2020-02-05 2:58 ` [PATCH 12/14] KVM: selftests: Add dirty ring buffer test Peter Xu
2020-02-05 2:58 ` [PATCH 13/14] KVM: selftests: Let dirty_log_test async for dirty ring test Peter Xu
8 siblings, 0 replies; 25+ messages in thread
From: Peter Xu @ 2020-02-05 2:58 UTC (permalink / raw)
To: kvm, linux-kernel
Cc: dinechin, sean.j.christopherson, pbonzini, jasowang, yan.y.zhao,
mst, peterx, kevin.tian, alex.williamson, dgilbert, vkuznets
Provide a hook for the checks after vcpu_run() completes. Preparation
for the dirty ring test because we'll need to take care of another
exit reason.
Since at it, drop the pages_count because after all we have a better
summary right now with statistics, and clean it up a bit.
Signed-off-by: Peter Xu <peterx@redhat.com>
---
tools/testing/selftests/kvm/dirty_log_test.c | 39 ++++++++++++--------
1 file changed, 23 insertions(+), 16 deletions(-)
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index a8ae8c0042a8..3542311f56ff 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -168,6 +168,15 @@ static void clear_log_collect_dirty_pages(struct kvm_vm *vm, int slot,
kvm_vm_clear_dirty_log(vm, slot, bitmap, 0, num_pages);
}
+static void default_after_vcpu_run(struct kvm_vm *vm)
+{
+ struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+
+ TEST_ASSERT(get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC,
+ "Invalid guest sync status: exit_reason=%s\n",
+ exit_reason_str(run->exit_reason));
+}
+
struct log_mode {
const char *name;
/* Hook when the vm creation is done (before vcpu creation) */
@@ -175,16 +184,20 @@ struct log_mode {
/* Hook to collect the dirty pages into the bitmap provided */
void (*collect_dirty_pages) (struct kvm_vm *vm, int slot,
void *bitmap, uint32_t num_pages);
+ /* Hook to call when after each vcpu run */
+ void (*after_vcpu_run)(struct kvm_vm *vm);
} log_modes[LOG_MODE_NUM] = {
{
.name = "dirty-log",
.create_vm_done = NULL,
.collect_dirty_pages = dirty_log_collect_dirty_pages,
+ .after_vcpu_run = default_after_vcpu_run,
},
{
.name = "clear-log",
.create_vm_done = clear_log_create_vm_done,
.collect_dirty_pages = clear_log_collect_dirty_pages,
+ .after_vcpu_run = default_after_vcpu_run,
},
};
@@ -224,6 +237,14 @@ static void log_mode_collect_dirty_pages(struct kvm_vm *vm, int slot,
mode->collect_dirty_pages(vm, slot, bitmap, num_pages);
}
+static void log_mode_after_vcpu_run(struct kvm_vm *vm)
+{
+ struct log_mode *mode = &log_modes[host_log_mode];
+
+ if (mode->after_vcpu_run)
+ mode->after_vcpu_run(vm);
+}
+
static void generate_random_array(uint64_t *guest_array, uint64_t size)
{
uint64_t i;
@@ -237,31 +258,17 @@ static void *vcpu_worker(void *data)
int ret;
struct kvm_vm *vm = data;
uint64_t *guest_array;
- uint64_t pages_count = 0;
- struct kvm_run *run;
-
- run = vcpu_state(vm, VCPU_ID);
guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array);
- generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
while (!READ_ONCE(host_quit)) {
+ generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
/* Let the guest dirty the random pages */
ret = _vcpu_run(vm, VCPU_ID);
TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
- if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) {
- pages_count += TEST_PAGES_PER_LOOP;
- generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
- } else {
- TEST_ASSERT(false,
- "Invalid guest sync status: "
- "exit_reason=%s\n",
- exit_reason_str(run->exit_reason));
- }
+ log_mode_after_vcpu_run(vm);
}
- DEBUG("Dirtied %"PRIu64" pages\n", pages_count);
-
return NULL;
}
--
2.24.1
^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH 12/14] KVM: selftests: Add dirty ring buffer test
2020-02-05 2:58 ` [PATCH 04/14] KVM: Pass in kvm pointer into mark_page_dirty_in_slot() Peter Xu
` (6 preceding siblings ...)
2020-02-05 2:58 ` [PATCH 11/14] KVM: selftests: Introduce after_vcpu_run hook for dirty " Peter Xu
@ 2020-02-05 2:58 ` Peter Xu
2020-02-05 2:58 ` [PATCH 13/14] KVM: selftests: Let dirty_log_test async for dirty ring test Peter Xu
8 siblings, 0 replies; 25+ messages in thread
From: Peter Xu @ 2020-02-05 2:58 UTC (permalink / raw)
To: kvm, linux-kernel
Cc: dinechin, sean.j.christopherson, pbonzini, jasowang, yan.y.zhao,
mst, peterx, kevin.tian, alex.williamson, dgilbert, vkuznets
Add the initial dirty ring buffer test.
The current test implements the userspace dirty ring collection, by
only reaping the dirty ring when the ring is full.
So it's still running synchronously like this:
vcpu main thread
1. vcpu dirties pages
2. vcpu gets dirty ring full
(userspace exit)
3. main thread waits until full
(so hardware buffers flushed)
4. main thread collects
5. main thread continues vcpu
6. vcpu continues, goes back to 1
We can't directly collects dirty bits during vcpu execution because
otherwise we can't guarantee the hardware dirty bits were flushed when
we collect and we're very strict on the dirty bits so otherwise we can
fail the future verify procedure. A follow up patch will make this
test to support async just like the existing dirty log test, by adding
a vcpu kick mechanism.
Signed-off-by: Peter Xu <peterx@redhat.com>
---
tools/testing/selftests/kvm/dirty_log_test.c | 195 +++++++++++++++++-
.../testing/selftests/kvm/include/kvm_util.h | 3 +
tools/testing/selftests/kvm/lib/kvm_util.c | 68 ++++++
.../selftests/kvm/lib/kvm_util_internal.h | 4 +
4 files changed, 268 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index 3542311f56ff..b4c210f33dd7 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -12,8 +12,10 @@
#include <unistd.h>
#include <time.h>
#include <pthread.h>
+#include <semaphore.h>
#include <linux/bitmap.h>
#include <linux/bitops.h>
+#include <asm/barrier.h>
#include "test_util.h"
#include "kvm_util.h"
@@ -57,6 +59,8 @@
# define test_and_clear_bit_le test_and_clear_bit
#endif
+#define TEST_DIRTY_RING_COUNT 1024
+
/*
* Guest/Host shared variables. Ensure addr_gva2hva() and/or
* sync_global_to/from_guest() are used when accessing from
@@ -128,6 +132,10 @@ static uint64_t host_dirty_count;
static uint64_t host_clear_count;
static uint64_t host_track_next_count;
+/* Whether dirty ring reset is requested, or finished */
+static sem_t dirty_ring_vcpu_stop;
+static sem_t dirty_ring_vcpu_cont;
+
enum log_mode_t {
/* Only use KVM_GET_DIRTY_LOG for logging */
LOG_MODE_DIRTY_LOG = 0,
@@ -135,6 +143,9 @@ enum log_mode_t {
/* Use both KVM_[GET|CLEAR]_DIRTY_LOG for logging */
LOG_MODE_CLERA_LOG = 1,
+ /* Use dirty ring for logging */
+ LOG_MODE_DIRTY_RING = 2,
+
LOG_MODE_NUM,
};
@@ -177,6 +188,115 @@ static void default_after_vcpu_run(struct kvm_vm *vm)
exit_reason_str(run->exit_reason));
}
+static void dirty_ring_create_vm_done(struct kvm_vm *vm)
+{
+ /*
+ * Switch to dirty ring mode after VM creation but before any
+ * of the vcpu creation.
+ */
+ vm_enable_dirty_ring(vm, TEST_DIRTY_RING_COUNT *
+ sizeof(struct kvm_dirty_gfn));
+}
+
+static inline bool dirty_gfn_is_dirtied(struct kvm_dirty_gfn *gfn)
+{
+ return gfn->flags == KVM_DIRTY_GFN_F_DIRTY;
+}
+
+static inline void dirty_gfn_set_collected(struct kvm_dirty_gfn *gfn)
+{
+ gfn->flags = KVM_DIRTY_GFN_F_RESET;
+}
+
+static uint32_t dirty_ring_collect_one(struct kvm_dirty_gfn *dirty_gfns,
+ int slot, void *bitmap,
+ uint32_t num_pages, uint32_t *fetch_index)
+{
+ struct kvm_dirty_gfn *cur;
+ uint32_t count = 0;
+
+ while (true) {
+ cur = &dirty_gfns[*fetch_index % TEST_DIRTY_RING_COUNT];
+ if (!dirty_gfn_is_dirtied(cur))
+ break;
+ TEST_ASSERT(cur->slot == slot, "Slot number didn't match: "
+ "%u != %u", cur->slot, slot);
+ TEST_ASSERT(cur->offset < num_pages, "Offset overflow: "
+ "0x%llx >= 0x%llx", cur->offset, num_pages);
+ DEBUG("fetch 0x%x page %llu\n", *fetch_index, cur->offset);
+ set_bit(cur->offset, bitmap);
+ dirty_gfn_set_collected(cur);
+ (*fetch_index)++;
+ count++;
+ }
+
+ return count;
+}
+
+static void dirty_ring_collect_dirty_pages(struct kvm_vm *vm, int slot,
+ void *bitmap, uint32_t num_pages)
+{
+ /* We only have one vcpu */
+ static uint32_t fetch_index = 0;
+ uint32_t count = 0, cleared;
+
+ /*
+ * Before fetching the dirty pages, we need a vmexit of the
+ * worker vcpu to make sure the hardware dirty buffers were
+ * flushed. This is not needed for dirty-log/clear-log tests
+ * because get dirty log will natually do so.
+ *
+ * For now we do it in the simple way - we simply wait until
+ * the vcpu uses up the soft dirty ring, then it'll always
+ * do a vmexit to make sure that PML buffers will be flushed.
+ * In real hypervisors, we probably need a vcpu kick or to
+ * stop the vcpus (before the final sync) to make sure we'll
+ * get all the existing dirty PFNs even cached in hardware.
+ */
+ sem_wait(&dirty_ring_vcpu_stop);
+
+ /* Only have one vcpu */
+ count = dirty_ring_collect_one(vcpu_map_dirty_ring(vm, VCPU_ID),
+ slot, bitmap, num_pages, &fetch_index);
+
+ cleared = kvm_vm_reset_dirty_ring(vm);
+
+ /* Cleared pages should be the same as collected */
+ TEST_ASSERT(cleared == count, "Reset dirty pages (%u) mismatch "
+ "with collected (%u)", cleared, count);
+
+ DEBUG("Notifying vcpu to continue\n");
+ sem_post(&dirty_ring_vcpu_cont);
+
+ DEBUG("Iteration %ld collected %u pages\n", iteration, count);
+}
+
+static void dirty_ring_after_vcpu_run(struct kvm_vm *vm)
+{
+ struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+
+ /* A ucall-sync or ring-full event is allowed */
+ if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) {
+ /* We should allow this to continue */
+ ;
+ } else if (run->exit_reason == KVM_EXIT_DIRTY_RING_FULL) {
+ sem_post(&dirty_ring_vcpu_stop);
+ DEBUG("vcpu stops because dirty ring full...\n");
+ sem_wait(&dirty_ring_vcpu_cont);
+ DEBUG("vcpu continues now.\n");
+ } else {
+ TEST_ASSERT(false, "Invalid guest sync status: "
+ "exit_reason=%s\n",
+ exit_reason_str(run->exit_reason));
+ }
+}
+
+static void dirty_ring_before_vcpu_join(void)
+{
+ /* Kick another round of vcpu just to make sure it will quit */
+ sem_post(&dirty_ring_vcpu_cont);
+}
+
struct log_mode {
const char *name;
/* Hook when the vm creation is done (before vcpu creation) */
@@ -186,6 +306,7 @@ struct log_mode {
void *bitmap, uint32_t num_pages);
/* Hook to call when after each vcpu run */
void (*after_vcpu_run)(struct kvm_vm *vm);
+ void (*before_vcpu_join) (void);
} log_modes[LOG_MODE_NUM] = {
{
.name = "dirty-log",
@@ -199,6 +320,13 @@ struct log_mode {
.collect_dirty_pages = clear_log_collect_dirty_pages,
.after_vcpu_run = default_after_vcpu_run,
},
+ {
+ .name = "dirty-ring",
+ .create_vm_done = dirty_ring_create_vm_done,
+ .collect_dirty_pages = dirty_ring_collect_dirty_pages,
+ .before_vcpu_join = dirty_ring_before_vcpu_join,
+ .after_vcpu_run = dirty_ring_after_vcpu_run,
+ },
};
/*
@@ -245,6 +373,14 @@ static void log_mode_after_vcpu_run(struct kvm_vm *vm)
mode->after_vcpu_run(vm);
}
+static void log_mode_before_vcpu_join(void)
+{
+ struct log_mode *mode = &log_modes[host_log_mode];
+
+ if (mode->before_vcpu_join)
+ mode->before_vcpu_join();
+}
+
static void generate_random_array(uint64_t *guest_array, uint64_t size)
{
uint64_t i;
@@ -292,14 +428,65 @@ static void vm_dirty_log_verify(unsigned long *bmap)
}
if (test_and_clear_bit_le(page, bmap)) {
+ bool matched;
+
host_dirty_count++;
+
/*
* If the bit is set, the value written onto
* the corresponding page should be either the
* previous iteration number or the current one.
*/
- TEST_ASSERT(*value_ptr == iteration ||
- *value_ptr == iteration - 1,
+ matched = (*value_ptr == iteration ||
+ *value_ptr == iteration - 1);
+
+ if (host_log_mode == LOG_MODE_DIRTY_RING && !matched) {
+ if (*value_ptr == iteration - 2) {
+ /*
+ * Short answer: this case is special
+ * only for dirty ring test where the
+ * page is the last page before a kvm
+ * dirty ring full in iteration N-2.
+ *
+ * Long answer: Assuming ring size R,
+ * one possible condition is:
+ *
+ * main thr vcpu thr
+ * -------- --------
+ * iter=1
+ * write 1 to page 0~(R-1)
+ * full, vmexit
+ * collect 0~(R-1)
+ * kick vcpu
+ * write 1 to (R-1)~(2R-2)
+ * full, vmexit
+ * iter=2
+ * collect (R-1)~(2R-2)
+ * kick vcpu
+ * write 1 to (2R-2)
+ * (NOTE!!! "1" cached in cpu reg)
+ * write 2 to (2R-1)~(3R-3)
+ * full, vmexit
+ * iter=3
+ * collect (2R-2)~(3R-3)
+ * (here if we read value on page
+ * "2R-2" is 1, while iter=3!!!)
+ */
+ matched = true;
+ } else {
+ /*
+ * This is also special for dirty ring
+ * when this page is exactly the last
+ * page touched before vcpu ring full.
+ * If it happens, we should expect the
+ * value to change in the next round.
+ */
+ set_bit_le(page, host_bmap_track);
+ continue;
+ }
+ }
+
+ TEST_ASSERT(matched,
"Set page %"PRIu64" value %"PRIu64
" incorrect (iteration=%"PRIu64")",
page, *value_ptr, iteration);
@@ -460,6 +647,7 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations,
/* Tell the vcpu thread to quit */
host_quit = true;
+ log_mode_before_vcpu_join();
pthread_join(vcpu_thread, NULL);
DEBUG("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), "
@@ -524,6 +712,9 @@ int main(int argc, char *argv[])
unsigned int host_ipa_limit;
#endif
+ sem_init(&dirty_ring_vcpu_stop, 0, 0);
+ sem_init(&dirty_ring_vcpu_cont, 0, 0);
+
#ifdef __x86_64__
vm_guest_mode_params_init(VM_MODE_PXXV48_4K, true, true);
#endif
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 29cccaf96baf..4b78a8d3e773 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -67,6 +67,7 @@ enum vm_mem_backing_src_type {
int kvm_check_cap(long cap);
int vm_enable_cap(struct kvm_vm *vm, struct kvm_enable_cap *cap);
+void vm_enable_dirty_ring(struct kvm_vm *vm, uint32_t ring_size);
struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm);
struct kvm_vm *_vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm);
@@ -76,6 +77,7 @@ void kvm_vm_release(struct kvm_vm *vmp);
void kvm_vm_get_dirty_log(struct kvm_vm *vm, int slot, void *log);
void kvm_vm_clear_dirty_log(struct kvm_vm *vm, int slot, void *log,
uint64_t first_page, uint32_t num_pages);
+uint32_t kvm_vm_reset_dirty_ring(struct kvm_vm *vm);
int kvm_memcmp_hva_gva(void *hva, struct kvm_vm *vm, const vm_vaddr_t gva,
size_t len);
@@ -137,6 +139,7 @@ void vcpu_nested_state_get(struct kvm_vm *vm, uint32_t vcpuid,
int vcpu_nested_state_set(struct kvm_vm *vm, uint32_t vcpuid,
struct kvm_nested_state *state, bool ignore_error);
#endif
+void *vcpu_map_dirty_ring(struct kvm_vm *vm, uint32_t vcpuid);
const char *exit_reason_str(unsigned int exit_reason);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 31253b4fa12f..25edf20d1962 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -85,6 +85,26 @@ int vm_enable_cap(struct kvm_vm *vm, struct kvm_enable_cap *cap)
return ret;
}
+void vm_enable_dirty_ring(struct kvm_vm *vm, uint32_t ring_size)
+{
+ struct kvm_enable_cap cap = {};
+ int ret;
+
+ ret = kvm_check_cap(KVM_CAP_DIRTY_LOG_RING);
+
+ TEST_ASSERT(ret >= 0, "KVM_CAP_DIRTY_LOG_RING");
+
+ if (ret == 0) {
+ fprintf(stderr, "KVM does not support dirty ring, skipping tests\n");
+ exit(KSFT_SKIP);
+ }
+
+ cap.cap = KVM_CAP_DIRTY_LOG_RING;
+ cap.args[0] = ring_size;
+ vm_enable_cap(vm, &cap);
+ vm->dirty_ring_size = ring_size;
+}
+
static void vm_open(struct kvm_vm *vm, int perm)
{
vm->kvm_fd = open(KVM_DEV_PATH, perm);
@@ -299,6 +319,11 @@ void kvm_vm_clear_dirty_log(struct kvm_vm *vm, int slot, void *log,
strerror(-ret));
}
+uint32_t kvm_vm_reset_dirty_ring(struct kvm_vm *vm)
+{
+ return ioctl(vm->fd, KVM_RESET_DIRTY_RINGS);
+}
+
/*
* Userspace Memory Region Find
*
@@ -410,6 +435,13 @@ static void vm_vcpu_rm(struct kvm_vm *vm, uint32_t vcpuid)
struct vcpu *vcpu = vcpu_find(vm, vcpuid);
int ret;
+ if (vcpu->dirty_gfns) {
+ ret = munmap(vcpu->dirty_gfns, vm->dirty_ring_size);
+ TEST_ASSERT(ret == 0, "munmap of VCPU dirty ring failed, "
+ "rc: %i errno: %i", ret, errno);
+ vcpu->dirty_gfns = NULL;
+ }
+
ret = munmap(vcpu->state, sizeof(*vcpu->state));
TEST_ASSERT(ret == 0, "munmap of VCPU fd failed, rc: %i "
"errno: %i", ret, errno);
@@ -1425,6 +1457,41 @@ int _vcpu_ioctl(struct kvm_vm *vm, uint32_t vcpuid,
return ret;
}
+void *vcpu_map_dirty_ring(struct kvm_vm *vm, uint32_t vcpuid)
+{
+ struct vcpu *vcpu;
+ uint32_t size = vm->dirty_ring_size;
+
+ TEST_ASSERT(size > 0, "Should enable dirty ring first");
+
+ vcpu = vcpu_find(vm, vcpuid);
+
+ TEST_ASSERT(vcpu, "Cannot find vcpu %u", vcpuid);
+
+ if (!vcpu->dirty_gfns) {
+ void *addr;
+
+ addr = mmap(NULL, size, PROT_READ,
+ MAP_PRIVATE, vcpu->fd,
+ vm->page_size * KVM_DIRTY_LOG_PAGE_OFFSET);
+ TEST_ASSERT(addr == MAP_FAILED, "Dirty ring mapped private");
+
+ addr = mmap(NULL, size, PROT_READ | PROT_EXEC,
+ MAP_PRIVATE, vcpu->fd,
+ vm->page_size * KVM_DIRTY_LOG_PAGE_OFFSET);
+ TEST_ASSERT(addr == MAP_FAILED, "Dirty ring mapped exec");
+
+ addr = mmap(NULL, size, PROT_READ | PROT_WRITE,
+ MAP_SHARED, vcpu->fd,
+ vm->page_size * KVM_DIRTY_LOG_PAGE_OFFSET);
+
+ vcpu->dirty_gfns = addr;
+ vcpu->dirty_gfns_count = size / sizeof(struct kvm_dirty_gfn);
+ }
+
+ return vcpu->dirty_gfns;
+}
+
/*
* VM Ioctl
*
@@ -1519,6 +1586,7 @@ static struct exit_reason {
{KVM_EXIT_INTERNAL_ERROR, "INTERNAL_ERROR"},
{KVM_EXIT_OSI, "OSI"},
{KVM_EXIT_PAPR_HCALL, "PAPR_HCALL"},
+ {KVM_EXIT_DIRTY_RING_FULL, "DIRTY_RING_FULL"},
#ifdef KVM_EXIT_MEMORY_NOT_PRESENT
{KVM_EXIT_MEMORY_NOT_PRESENT, "MEMORY_NOT_PRESENT"},
#endif
diff --git a/tools/testing/selftests/kvm/lib/kvm_util_internal.h b/tools/testing/selftests/kvm/lib/kvm_util_internal.h
index ac50c42750cf..452e1f02611a 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util_internal.h
+++ b/tools/testing/selftests/kvm/lib/kvm_util_internal.h
@@ -39,6 +39,9 @@ struct vcpu {
uint32_t id;
int fd;
struct kvm_run *state;
+ struct kvm_dirty_gfn *dirty_gfns;
+ uint32_t fetch_index;
+ uint32_t dirty_gfns_count;
};
struct kvm_vm {
@@ -61,6 +64,7 @@ struct kvm_vm {
vm_paddr_t pgd;
vm_vaddr_t gdt;
vm_vaddr_t tss;
+ uint32_t dirty_ring_size;
};
struct vcpu *vcpu_find(struct kvm_vm *vm, uint32_t vcpuid);
--
2.24.1
^ permalink raw reply related [flat|nested] 25+ messages in thread
* [PATCH 13/14] KVM: selftests: Let dirty_log_test async for dirty ring test
2020-02-05 2:58 ` [PATCH 04/14] KVM: Pass in kvm pointer into mark_page_dirty_in_slot() Peter Xu
` (7 preceding siblings ...)
2020-02-05 2:58 ` [PATCH 12/14] KVM: selftests: Add dirty ring buffer test Peter Xu
@ 2020-02-05 2:58 ` Peter Xu
2020-02-05 9:48 ` Andrew Jones
8 siblings, 1 reply; 25+ messages in thread
From: Peter Xu @ 2020-02-05 2:58 UTC (permalink / raw)
To: kvm, linux-kernel
Cc: dinechin, sean.j.christopherson, pbonzini, jasowang, yan.y.zhao,
mst, peterx, kevin.tian, alex.williamson, dgilbert, vkuznets
Previously the dirty ring test was working in synchronous way, because
only with a vmexit (with that it was the ring full event) we'll know
the hardware dirty bits will be flushed to the dirty ring.
With this patch we first introduced the vcpu kick mechanism by using
SIGUSR1, meanwhile we can have a guarantee of vmexit and also the
flushing of hardware dirty bits. With all these, we can keep the vcpu
dirty work asynchronous of the whole collection procedure now. Still,
we need to be very careful that we can only do it async if the vcpu is
not reaching soft limit (no KVM_EXIT_DIRTY_RING_FULL). Otherwise we
must collect the dirty bits before continuing the vcpu.
Further increase the dirty ring size to current maximum to make sure
we torture more on the no-ring-full case, which should be the major
scenario when the hypervisors like QEMU would like to use this feature.
Signed-off-by: Peter Xu <peterx@redhat.com>
---
tools/testing/selftests/kvm/dirty_log_test.c | 123 +++++++++++++-----
.../testing/selftests/kvm/include/kvm_util.h | 1 +
tools/testing/selftests/kvm/lib/kvm_util.c | 8 ++
3 files changed, 103 insertions(+), 29 deletions(-)
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index b4c210f33dd7..6c754e91fc50 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -13,6 +13,9 @@
#include <time.h>
#include <pthread.h>
#include <semaphore.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <errno.h>
#include <linux/bitmap.h>
#include <linux/bitops.h>
#include <asm/barrier.h>
@@ -59,7 +62,9 @@
# define test_and_clear_bit_le test_and_clear_bit
#endif
-#define TEST_DIRTY_RING_COUNT 1024
+#define TEST_DIRTY_RING_COUNT 65536
+
+#define SIG_IPI SIGUSR1
/*
* Guest/Host shared variables. Ensure addr_gva2hva() and/or
@@ -135,6 +140,12 @@ static uint64_t host_track_next_count;
/* Whether dirty ring reset is requested, or finished */
static sem_t dirty_ring_vcpu_stop;
static sem_t dirty_ring_vcpu_cont;
+/*
+ * This is updated by the vcpu thread to tell the host whether it's a
+ * ring-full event. It should only be read until a sem_wait() of
+ * dirty_ring_vcpu_stop and before vcpu continues to run.
+ */
+static bool dirty_ring_vcpu_ring_full;
enum log_mode_t {
/* Only use KVM_GET_DIRTY_LOG for logging */
@@ -151,6 +162,33 @@ enum log_mode_t {
/* Mode of logging. Default is LOG_MODE_DIRTY_LOG */
static enum log_mode_t host_log_mode;
+pthread_t vcpu_thread;
+
+/* Only way to pass this to the signal handler */
+struct kvm_vm *current_vm;
+
+static void vcpu_sig_handler(int sig)
+{
+ TEST_ASSERT(sig == SIG_IPI, "unknown signal: %d", sig);
+}
+
+static void vcpu_kick(void)
+{
+ pthread_kill(vcpu_thread, SIG_IPI);
+}
+
+/*
+ * In our test we do signal tricks, let's use a better version of
+ * sem_wait to avoid signal interrupts
+ */
+static void sem_wait_until(sem_t *sem)
+{
+ int ret;
+
+ do
+ ret = sem_wait(sem);
+ while (ret == -1 && errno == EINTR);
+}
static void clear_log_create_vm_done(struct kvm_vm *vm)
{
@@ -179,10 +217,13 @@ static void clear_log_collect_dirty_pages(struct kvm_vm *vm, int slot,
kvm_vm_clear_dirty_log(vm, slot, bitmap, 0, num_pages);
}
-static void default_after_vcpu_run(struct kvm_vm *vm)
+static void default_after_vcpu_run(struct kvm_vm *vm, int ret, int err)
{
struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+ TEST_ASSERT(ret == 0 || (ret == -1 && err == EINTR),
+ "vcpu run failed: errno=%d", err);
+
TEST_ASSERT(get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC,
"Invalid guest sync status: exit_reason=%s\n",
exit_reason_str(run->exit_reason));
@@ -233,27 +274,37 @@ static uint32_t dirty_ring_collect_one(struct kvm_dirty_gfn *dirty_gfns,
return count;
}
+static void dirty_ring_wait_vcpu(void)
+{
+ /* This makes sure that hardware PML cache flushed */
+ vcpu_kick();
+ sem_wait_until(&dirty_ring_vcpu_stop);
+}
+
+static void dirty_ring_continue_vcpu(void)
+{
+ DEBUG("Notifying vcpu to continue\n");
+ sem_post(&dirty_ring_vcpu_cont);
+}
+
static void dirty_ring_collect_dirty_pages(struct kvm_vm *vm, int slot,
void *bitmap, uint32_t num_pages)
{
/* We only have one vcpu */
static uint32_t fetch_index = 0;
uint32_t count = 0, cleared;
+ bool continued_vcpu = false;
- /*
- * Before fetching the dirty pages, we need a vmexit of the
- * worker vcpu to make sure the hardware dirty buffers were
- * flushed. This is not needed for dirty-log/clear-log tests
- * because get dirty log will natually do so.
- *
- * For now we do it in the simple way - we simply wait until
- * the vcpu uses up the soft dirty ring, then it'll always
- * do a vmexit to make sure that PML buffers will be flushed.
- * In real hypervisors, we probably need a vcpu kick or to
- * stop the vcpus (before the final sync) to make sure we'll
- * get all the existing dirty PFNs even cached in hardware.
- */
- sem_wait(&dirty_ring_vcpu_stop);
+ dirty_ring_wait_vcpu();
+
+ if (!dirty_ring_vcpu_ring_full) {
+ /*
+ * This is not a ring-full event, it's safe to allow
+ * vcpu to continue
+ */
+ dirty_ring_continue_vcpu();
+ continued_vcpu = true;
+ }
/* Only have one vcpu */
count = dirty_ring_collect_one(vcpu_map_dirty_ring(vm, VCPU_ID),
@@ -265,13 +316,16 @@ static void dirty_ring_collect_dirty_pages(struct kvm_vm *vm, int slot,
TEST_ASSERT(cleared == count, "Reset dirty pages (%u) mismatch "
"with collected (%u)", cleared, count);
- DEBUG("Notifying vcpu to continue\n");
- sem_post(&dirty_ring_vcpu_cont);
+ if (!continued_vcpu) {
+ TEST_ASSERT(dirty_ring_vcpu_ring_full,
+ "Didn't continue vcpu even without ring full");
+ dirty_ring_continue_vcpu();
+ }
DEBUG("Iteration %ld collected %u pages\n", iteration, count);
}
-static void dirty_ring_after_vcpu_run(struct kvm_vm *vm)
+static void dirty_ring_after_vcpu_run(struct kvm_vm *vm, int ret, int err)
{
struct kvm_run *run = vcpu_state(vm, VCPU_ID);
@@ -279,10 +333,16 @@ static void dirty_ring_after_vcpu_run(struct kvm_vm *vm)
if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) {
/* We should allow this to continue */
;
- } else if (run->exit_reason == KVM_EXIT_DIRTY_RING_FULL) {
+ } else if (run->exit_reason == KVM_EXIT_DIRTY_RING_FULL ||
+ (ret == -1 && err == EINTR)) {
+ /* Update the flag first before pause */
+ WRITE_ONCE(dirty_ring_vcpu_ring_full,
+ run->exit_reason == KVM_EXIT_DIRTY_RING_FULL);
sem_post(&dirty_ring_vcpu_stop);
- DEBUG("vcpu stops because dirty ring full...\n");
- sem_wait(&dirty_ring_vcpu_cont);
+ DEBUG("vcpu stops because %s...\n",
+ dirty_ring_vcpu_ring_full ?
+ "dirty ring is full" : "vcpu is kicked out");
+ sem_wait_until(&dirty_ring_vcpu_cont);
DEBUG("vcpu continues now.\n");
} else {
TEST_ASSERT(false, "Invalid guest sync status: "
@@ -305,7 +365,7 @@ struct log_mode {
void (*collect_dirty_pages) (struct kvm_vm *vm, int slot,
void *bitmap, uint32_t num_pages);
/* Hook to call when after each vcpu run */
- void (*after_vcpu_run)(struct kvm_vm *vm);
+ void (*after_vcpu_run)(struct kvm_vm *vm, int ret, int err);
void (*before_vcpu_join) (void);
} log_modes[LOG_MODE_NUM] = {
{
@@ -365,12 +425,12 @@ static void log_mode_collect_dirty_pages(struct kvm_vm *vm, int slot,
mode->collect_dirty_pages(vm, slot, bitmap, num_pages);
}
-static void log_mode_after_vcpu_run(struct kvm_vm *vm)
+static void log_mode_after_vcpu_run(struct kvm_vm *vm, int ret, int err)
{
struct log_mode *mode = &log_modes[host_log_mode];
if (mode->after_vcpu_run)
- mode->after_vcpu_run(vm);
+ mode->after_vcpu_run(vm, ret, err);
}
static void log_mode_before_vcpu_join(void)
@@ -394,15 +454,21 @@ static void *vcpu_worker(void *data)
int ret;
struct kvm_vm *vm = data;
uint64_t *guest_array;
+ struct sigaction sigact;
+
+ current_vm = vm;
+ memset(&sigact, 0, sizeof(sigact));
+ sigact.sa_handler = vcpu_sig_handler;
+ sigaction(SIG_IPI, &sigact, NULL);
guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array);
while (!READ_ONCE(host_quit)) {
+ /* Clear any existing kick signals */
generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
/* Let the guest dirty the random pages */
- ret = _vcpu_run(vm, VCPU_ID);
- TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
- log_mode_after_vcpu_run(vm);
+ ret = __vcpu_run(vm, VCPU_ID);
+ log_mode_after_vcpu_run(vm, ret, errno);
}
return NULL;
@@ -549,7 +615,6 @@ static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,
static void run_test(enum vm_guest_mode mode, unsigned long iterations,
unsigned long interval, uint64_t phys_offset)
{
- pthread_t vcpu_thread;
struct kvm_vm *vm;
unsigned long *bmap;
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 4b78a8d3e773..e64fbfe6bbd5 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -115,6 +115,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva);
struct kvm_run *vcpu_state(struct kvm_vm *vm, uint32_t vcpuid);
void vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
+int __vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid);
void vcpu_set_mp_state(struct kvm_vm *vm, uint32_t vcpuid,
struct kvm_mp_state *mp_state);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 25edf20d1962..5137882503bd 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -1203,6 +1203,14 @@ int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid)
return rc;
}
+int __vcpu_run(struct kvm_vm *vm, uint32_t vcpuid)
+{
+ struct vcpu *vcpu = vcpu_find(vm, vcpuid);
+
+ TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid);
+ return ioctl(vcpu->fd, KVM_RUN, NULL);
+}
+
void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid)
{
struct vcpu *vcpu = vcpu_find(vm, vcpuid);
--
2.24.1
^ permalink raw reply related [flat|nested] 25+ messages in thread
* Re: [PATCH 13/14] KVM: selftests: Let dirty_log_test async for dirty ring test
2020-02-05 2:58 ` [PATCH 13/14] KVM: selftests: Let dirty_log_test async for dirty ring test Peter Xu
@ 2020-02-05 9:48 ` Andrew Jones
2020-02-05 15:55 ` Peter Xu
0 siblings, 1 reply; 25+ messages in thread
From: Andrew Jones @ 2020-02-05 9:48 UTC (permalink / raw)
To: Peter Xu
Cc: kvm, linux-kernel, dinechin, sean.j.christopherson, pbonzini,
jasowang, yan.y.zhao, mst, kevin.tian, alex.williamson, dgilbert,
vkuznets
On Tue, Feb 04, 2020 at 09:58:41PM -0500, Peter Xu wrote:
> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> index 4b78a8d3e773..e64fbfe6bbd5 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -115,6 +115,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva);
> struct kvm_run *vcpu_state(struct kvm_vm *vm, uint32_t vcpuid);
> void vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
> int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
> +int __vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
> void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid);
> void vcpu_set_mp_state(struct kvm_vm *vm, uint32_t vcpuid,
> struct kvm_mp_state *mp_state);
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 25edf20d1962..5137882503bd 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -1203,6 +1203,14 @@ int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid)
> return rc;
> }
>
> +int __vcpu_run(struct kvm_vm *vm, uint32_t vcpuid)
> +{
> + struct vcpu *vcpu = vcpu_find(vm, vcpuid);
> +
> + TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid);
> + return ioctl(vcpu->fd, KVM_RUN, NULL);
> +}
> +
> void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid)
> {
> struct vcpu *vcpu = vcpu_find(vm, vcpuid);
I think we should add a vcpu_get_fd(vm, vcpuid) function instead, and
then call ioctl directly from the test.
Thanks,
drew
^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH 13/14] KVM: selftests: Let dirty_log_test async for dirty ring test
2020-02-05 9:48 ` Andrew Jones
@ 2020-02-05 15:55 ` Peter Xu
2020-02-05 17:15 ` Andrew Jones
0 siblings, 1 reply; 25+ messages in thread
From: Peter Xu @ 2020-02-05 15:55 UTC (permalink / raw)
To: Andrew Jones
Cc: kvm, linux-kernel, dinechin, sean.j.christopherson, pbonzini,
jasowang, yan.y.zhao, mst, kevin.tian, alex.williamson, dgilbert,
vkuznets
On Wed, Feb 05, 2020 at 10:48:06AM +0100, Andrew Jones wrote:
> On Tue, Feb 04, 2020 at 09:58:41PM -0500, Peter Xu wrote:
> > diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> > index 4b78a8d3e773..e64fbfe6bbd5 100644
> > --- a/tools/testing/selftests/kvm/include/kvm_util.h
> > +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> > @@ -115,6 +115,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva);
> > struct kvm_run *vcpu_state(struct kvm_vm *vm, uint32_t vcpuid);
> > void vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
> > int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
> > +int __vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
> > void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid);
> > void vcpu_set_mp_state(struct kvm_vm *vm, uint32_t vcpuid,
> > struct kvm_mp_state *mp_state);
> > diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> > index 25edf20d1962..5137882503bd 100644
> > --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> > @@ -1203,6 +1203,14 @@ int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid)
> > return rc;
> > }
> >
> > +int __vcpu_run(struct kvm_vm *vm, uint32_t vcpuid)
> > +{
> > + struct vcpu *vcpu = vcpu_find(vm, vcpuid);
> > +
> > + TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid);
> > + return ioctl(vcpu->fd, KVM_RUN, NULL);
> > +}
> > +
> > void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid)
> > {
> > struct vcpu *vcpu = vcpu_find(vm, vcpuid);
>
> I think we should add a vcpu_get_fd(vm, vcpuid) function instead, and
> then call ioctl directly from the test.
Currently the vcpu struct is still internal to the lib/ directory (as
defined in lib/kvm_util_internal.h). Wit that, it seems the vcpu fd
should also be limited to the lib/ as well?
But I feel like I got your point, because when I worked on the
selftests I did notice that in many places it's easier to expose all
these things for test cases (e.g., the struct vcpu). For me, it's not
only for the vcpu fd, but also for the rest of internal structures to
be able to be accessed from tests directly. Not sure whether that's
what you thought too. It's just a separate topic of what this series
was trying to do.
Thanks,
--
Peter Xu
^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH 13/14] KVM: selftests: Let dirty_log_test async for dirty ring test
2020-02-05 15:55 ` Peter Xu
@ 2020-02-05 17:15 ` Andrew Jones
0 siblings, 0 replies; 25+ messages in thread
From: Andrew Jones @ 2020-02-05 17:15 UTC (permalink / raw)
To: Peter Xu
Cc: kvm, linux-kernel, dinechin, sean.j.christopherson, pbonzini,
jasowang, yan.y.zhao, mst, kevin.tian, alex.williamson, dgilbert,
vkuznets
On Wed, Feb 05, 2020 at 10:55:51AM -0500, Peter Xu wrote:
> On Wed, Feb 05, 2020 at 10:48:06AM +0100, Andrew Jones wrote:
> > On Tue, Feb 04, 2020 at 09:58:41PM -0500, Peter Xu wrote:
> > > diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> > > index 4b78a8d3e773..e64fbfe6bbd5 100644
> > > --- a/tools/testing/selftests/kvm/include/kvm_util.h
> > > +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> > > @@ -115,6 +115,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva);
> > > struct kvm_run *vcpu_state(struct kvm_vm *vm, uint32_t vcpuid);
> > > void vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
> > > int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
> > > +int __vcpu_run(struct kvm_vm *vm, uint32_t vcpuid);
> > > void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid);
> > > void vcpu_set_mp_state(struct kvm_vm *vm, uint32_t vcpuid,
> > > struct kvm_mp_state *mp_state);
> > > diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> > > index 25edf20d1962..5137882503bd 100644
> > > --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> > > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> > > @@ -1203,6 +1203,14 @@ int _vcpu_run(struct kvm_vm *vm, uint32_t vcpuid)
> > > return rc;
> > > }
> > >
> > > +int __vcpu_run(struct kvm_vm *vm, uint32_t vcpuid)
> > > +{
> > > + struct vcpu *vcpu = vcpu_find(vm, vcpuid);
> > > +
> > > + TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid);
> > > + return ioctl(vcpu->fd, KVM_RUN, NULL);
> > > +}
> > > +
> > > void vcpu_run_complete_io(struct kvm_vm *vm, uint32_t vcpuid)
> > > {
> > > struct vcpu *vcpu = vcpu_find(vm, vcpuid);
> >
> > I think we should add a vcpu_get_fd(vm, vcpuid) function instead, and
> > then call ioctl directly from the test.
>
> Currently the vcpu struct is still internal to the lib/ directory (as
> defined in lib/kvm_util_internal.h). Wit that, it seems the vcpu fd
> should also be limited to the lib/ as well?
>
> But I feel like I got your point, because when I worked on the
> selftests I did notice that in many places it's easier to expose all
> these things for test cases (e.g., the struct vcpu). For me, it's not
> only for the vcpu fd, but also for the rest of internal structures to
> be able to be accessed from tests directly. Not sure whether that's
> what you thought too. It's just a separate topic of what this series
> was trying to do.
So far I've just wished I could get to the fd, which seems reasonable
since it's an fd. I agree the whole internal thing is probably
unnecessary, but nobody (including me) has complained enough yet to
undo it. For this patch series I'd prefer we start heading in the
expose more direction, than in the yet another variant of vcpu_run
direction though.
Thanks,
drew
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