[Qemu-devel] [PATCH v7 3/4] tests: in IDE and AHCI tests perform DMA write before flushing

["Denis V. Lunev" <den@openvz.org>]

From: Evgeny Yakovlev <eyakovlev@virtuozzo.com>

Due to changes in flush behaviour clean disks stopped generating
flush_to_disk events and IDE and AHCI tests that test flush commands
started to fail.

This change adds additional DMA writes to affected tests before sending
flush commands so that bdrv_flush actually generates flush_to_disk event.

Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Fam Zheng <famz@redhat.com>
CC: John Snow <jsnow@redhat.com>
---
 tests/ahci-test.c | 34 ++++++++++++++++++++++++++++++++--
 tests/ide-test.c  | 43 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/tests/ahci-test.c b/tests/ahci-test.c
index 57dc44c..9c0adce 100644
--- a/tests/ahci-test.c
+++ b/tests/ahci-test.c
@@ -1063,11 +1063,34 @@ static void test_dma_fragmented(void)
     g_free(tx);
 }
 
+/*
+ * Write sector 1 with random data to make AHCI storage dirty
+ * Needed for flush tests so that flushes actually go though the block layer
+ */
+static void make_dirty(AHCIQState* ahci, uint8_t port)
+{
+    uint64_t ptr;
+    unsigned bufsize = 512;
+
+    ptr = ahci_alloc(ahci, bufsize);
+    g_assert(ptr);
+
+    ahci_guest_io(ahci, port, CMD_WRITE_DMA, ptr, bufsize, 1);
+    ahci_free(ahci, ptr);
+}
+
 static void test_flush(void)
 {
     AHCIQState *ahci;
+    uint8_t port;
 
     ahci = ahci_boot_and_enable(NULL);
+
+    port = ahci_port_select(ahci);
+    ahci_port_clear(ahci, port);
+
+    make_dirty(ahci, port);
+
     ahci_test_flush(ahci);
     ahci_shutdown(ahci);
 }
@@ -1087,10 +1110,13 @@ static void test_flush_retry(void)
                                 debug_path,
                                 tmp_path, imgfmt);
 
-    /* Issue Flush Command and wait for error */
     port = ahci_port_select(ahci);
     ahci_port_clear(ahci, port);
 
+    /* Issue write so that flush actually goes to disk */
+    make_dirty(ahci, port);
+
+    /* Issue Flush Command and wait for error */
     cmd = ahci_guest_io_halt(ahci, port, CMD_FLUSH_CACHE, 0, 0, 0);
     ahci_guest_io_resume(ahci, cmd);
 
@@ -1343,9 +1369,13 @@ static void test_flush_migrate(void)
 
     set_context(src->parent);
 
-    /* Issue Flush Command */
     px = ahci_port_select(src);
     ahci_port_clear(src, px);
+
+    /* Dirty device so that flush reaches disk */
+    make_dirty(src, px);
+
+    /* Issue Flush Command */
     cmd = ahci_command_create(CMD_FLUSH_CACHE);
     ahci_command_commit(src, cmd, px);
     ahci_command_issue_async(src, cmd);
diff --git a/tests/ide-test.c b/tests/ide-test.c
index fed1b2e..8466d0f 100644
--- a/tests/ide-test.c
+++ b/tests/ide-test.c
@@ -499,6 +499,39 @@ static void test_identify(void)
     ide_test_quit();
 }
 
+/*
+ * Write sector 1 with random data to make IDE storage dirty
+ * Needed for flush tests so that flushes actually go though the block layer
+ */
+static void make_dirty(uint8_t device)
+{
+    uint8_t status;
+    size_t len = 512;
+    uintptr_t guest_buf;
+    void* buf;
+
+    guest_buf = guest_alloc(guest_malloc, len);
+    buf = g_malloc(len);
+    g_assert(guest_buf);
+    g_assert(buf);
+
+    memwrite(guest_buf, buf, len);
+
+    PrdtEntry prdt[] = {
+        {
+            .addr = cpu_to_le32(guest_buf),
+            .size = cpu_to_le32(len | PRDT_EOT),
+        },
+    };
+
+    status = send_dma_request(CMD_WRITE_DMA, 1, 1, prdt,
+                              ARRAY_SIZE(prdt), NULL);
+    g_assert_cmphex(status, ==, BM_STS_INTR);
+    assert_bit_clear(inb(IDE_BASE + reg_status), DF | ERR);
+
+    g_free(buf);
+}
+
 static void test_flush(void)
 {
     uint8_t data;
@@ -507,6 +540,11 @@ static void test_flush(void)
         "-drive file=blkdebug::%s,if=ide,cache=writeback,format=raw",
         tmp_path);
 
+    qtest_irq_intercept_in(global_qtest, "ioapic");
+
+    /* Dirty media so that CMD_FLUSH_CACHE will actually go to disk */
+    make_dirty(0);
+
     /* Delay the completion of the flush request until we explicitly do it */
     g_free(hmp("qemu-io ide0-hd0 \"break flush_to_os A\""));
 
@@ -549,6 +587,11 @@ static void test_retry_flush(const char *machine)
         "rerror=stop,werror=stop",
         debug_path, tmp_path);
 
+    qtest_irq_intercept_in(global_qtest, "ioapic");
+
+    /* Dirty media so that CMD_FLUSH_CACHE will actually go to disk */
+    make_dirty(0);
+
     /* FLUSH CACHE command on device 0*/
     outb(IDE_BASE + reg_device, 0);
     outb(IDE_BASE + reg_command, CMD_FLUSH_CACHE);
-- 
2.1.4