This is a note to let you know that I've just added the patch titled
KVM: selftests: Clear dirty ring states between two modes in dirty_log_test
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-selftests-clear-dirty-ring-states-between-two-mo.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b81388a209f8a61ac75b88948e4da028974e2f2a
Author: Gavin Shan <gshan@xxxxxxxxxx>
Date: Thu Nov 10 18:49:13 2022 +0800
KVM: selftests: Clear dirty ring states between two modes in dirty_log_test
[ Upstream commit 7167190ddb863bd061c0c6b61f4cec94184b40da ]
There are two states, which need to be cleared before next mode
is executed. Otherwise, we will hit failure as the following messages
indicate.
- The variable 'dirty_ring_vcpu_ring_full' shared by main and vcpu
thread. It's indicating if the vcpu exit due to full ring buffer.
The value can be carried from previous mode (VM_MODE_P40V48_4K) to
current one (VM_MODE_P40V48_64K) when VM_MODE_P40V48_16K isn't
supported.
- The current ring buffer index needs to be reset before next mode
(VM_MODE_P40V48_64K) is executed. Otherwise, the stale value is
carried from previous mode (VM_MODE_P40V48_4K).
# ./dirty_log_test -M dirty-ring
Setting log mode to: 'dirty-ring'
Test iterations: 32, interval: 10 (ms)
Testing guest mode: PA-bits:40, VA-bits:48, 4K pages
guest physical test memory offset: 0xffbfffc000
:
Dirtied 995328 pages
Total bits checked: dirty (1012434), clear (7114123), track_next (966700)
Testing guest mode: PA-bits:40, VA-bits:48, 64K pages
guest physical test memory offset: 0xffbffc0000
vcpu stops because vcpu is kicked out...
vcpu continues now.
Notifying vcpu to continue
Iteration 1 collected 0 pages
vcpu stops because dirty ring is full...
vcpu continues now.
vcpu stops because dirty ring is full...
vcpu continues now.
vcpu stops because dirty ring is full...
==== Test Assertion Failure ====
dirty_log_test.c:369: cleared == count
pid=10541 tid=10541 errno=22 - Invalid argument
1 0x0000000000403087: dirty_ring_collect_dirty_pages at dirty_log_test.c:369
2 0x0000000000402a0b: log_mode_collect_dirty_pages at dirty_log_test.c:492
3 (inlined by) run_test at dirty_log_test.c:795
4 (inlined by) run_test at dirty_log_test.c:705
5 0x0000000000403a37: for_each_guest_mode at guest_modes.c:100
6 0x0000000000401ccf: main at dirty_log_test.c:938
7 0x0000ffff9ecd279b: ?? ??:0
8 0x0000ffff9ecd286b: ?? ??:0
9 0x0000000000401def: _start at ??:?
Reset dirty pages (0) mismatch with collected (35566)
Fix the issues by clearing 'dirty_ring_vcpu_ring_full' and the ring
buffer index before next new mode is to be executed.
Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20221110104914.31280-7-gshan@xxxxxxxxxx
Stable-dep-of: ba58f873cdee ("KVM: selftests: Fix a semaphore imbalance in the dirty ring logging test")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index b5234d6efbe1..8758c10ec850 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -226,13 +226,15 @@ static void clear_log_create_vm_done(struct kvm_vm *vm)
}
static void dirty_log_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
- void *bitmap, uint32_t num_pages)
+ void *bitmap, uint32_t num_pages,
+ uint32_t *unused)
{
kvm_vm_get_dirty_log(vcpu->vm, slot, bitmap);
}
static void clear_log_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
- void *bitmap, uint32_t num_pages)
+ void *bitmap, uint32_t num_pages,
+ uint32_t *unused)
{
kvm_vm_get_dirty_log(vcpu->vm, slot, bitmap);
kvm_vm_clear_dirty_log(vcpu->vm, slot, bitmap, 0, num_pages);
@@ -329,10 +331,9 @@ static void dirty_ring_continue_vcpu(void)
}
static void dirty_ring_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
- void *bitmap, uint32_t num_pages)
+ void *bitmap, uint32_t num_pages,
+ uint32_t *ring_buf_idx)
{
- /* We only have one vcpu */
- static uint32_t fetch_index = 0;
uint32_t count = 0, cleared;
bool continued_vcpu = false;
@@ -349,7 +350,8 @@ static void dirty_ring_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
/* Only have one vcpu */
count = dirty_ring_collect_one(vcpu_map_dirty_ring(vcpu),
- slot, bitmap, num_pages, &fetch_index);
+ slot, bitmap, num_pages,
+ ring_buf_idx);
cleared = kvm_vm_reset_dirty_ring(vcpu->vm);
@@ -406,7 +408,8 @@ struct log_mode {
void (*create_vm_done)(struct kvm_vm *vm);
/* Hook to collect the dirty pages into the bitmap provided */
void (*collect_dirty_pages) (struct kvm_vcpu *vcpu, int slot,
- void *bitmap, uint32_t num_pages);
+ void *bitmap, uint32_t num_pages,
+ uint32_t *ring_buf_idx);
/* Hook to call when after each vcpu run */
void (*after_vcpu_run)(struct kvm_vcpu *vcpu, int ret, int err);
void (*before_vcpu_join) (void);
@@ -471,13 +474,14 @@ static void log_mode_create_vm_done(struct kvm_vm *vm)
}
static void log_mode_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot,
- void *bitmap, uint32_t num_pages)
+ void *bitmap, uint32_t num_pages,
+ uint32_t *ring_buf_idx)
{
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(vcpu, slot, bitmap, num_pages);
+ mode->collect_dirty_pages(vcpu, slot, bitmap, num_pages, ring_buf_idx);
}
static void log_mode_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
@@ -696,6 +700,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
struct kvm_vcpu *vcpu;
struct kvm_vm *vm;
unsigned long *bmap;
+ uint32_t ring_buf_idx = 0;
if (!log_mode_supported()) {
print_skip("Log mode '%s' not supported",
@@ -771,6 +776,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
host_dirty_count = 0;
host_clear_count = 0;
host_track_next_count = 0;
+ WRITE_ONCE(dirty_ring_vcpu_ring_full, false);
pthread_create(&vcpu_thread, NULL, vcpu_worker, vcpu);
@@ -778,7 +784,8 @@ static void run_test(enum vm_guest_mode mode, void *arg)
/* Give the vcpu thread some time to dirty some pages */
usleep(p->interval * 1000);
log_mode_collect_dirty_pages(vcpu, TEST_MEM_SLOT_INDEX,
- bmap, host_num_pages);
+ bmap, host_num_pages,
+ &ring_buf_idx);
/*
* See vcpu_sync_stop_requested definition for details on why
