Merge remote-tracking branch 'remotes/jnsnow/tags/ide-pull-request' into staging

# gpg: Signature made Fri May 22 20:58:44 2015 BST using RSA key ID AAFC390E
# gpg: Good signature from "John Snow (John Huston) <jsnow@redhat.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: FAEB 9711 A12C F475 812F  18F2 88A9 064D 1835 61EB
#      Subkey fingerprint: F9B7 ABDB BCAC DF95 BE76  CBD0 7DEF 8106 AAFC 390E

* remotes/jnsnow/tags/ide-pull-request:
  ahci: do not remap clb/fis unconditionally
  macio: move unaligned DMA write code into separate pmac_dma_write() function
  macio: move unaligned DMA read code into separate pmac_dma_read() function
  qtest: pre-buffer hex nibs
  libqos/ahci: Swap memread/write with bufread/write
  qtest: add memset to qtest protocol
  qtest: Add base64 encoded read/write
  qtest: allow arbitrarily long sends
  qtest/ahci: add migrate halted dma test
  qtest/ahci: add halted dma test
  qtest/ahci: add flush migrate test
  qtest/ahci: add migrate dma test
  qtest/ahci: Add migration test
  ich9/ahci: Enable Migration
  libqos: Add migration helpers
  libqos/ahci: Fix sector set method
  libqos/ahci: Add halted command helpers
  glib: remove stale compat functions
  configure: require glib 2.22

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

9 files changed, 591 insertions, 36 deletions

diff --git a/tests/ahci-test.c b/tests/ahci-test.c
index 7c23bb2..6e3fa81 100644
--- a/tests/ahci-test.c
+++ b/tests/ahci-test.c
@@ -97,6 +97,72 @@ static void generate_pattern(void *buffer, size_t len, size_t cycle_len)
     }
 }
 
+/**
+ * Verify that the transfer did not corrupt our state at all.
+ */
+static void verify_state(AHCIQState *ahci)
+{
+    int i, j;
+    uint32_t ahci_fingerprint;
+    uint64_t hba_base;
+    uint64_t hba_stored;
+    AHCICommandHeader cmd;
+
+    ahci_fingerprint = qpci_config_readl(ahci->dev, PCI_VENDOR_ID);
+    g_assert_cmphex(ahci_fingerprint, ==, ahci->fingerprint);
+
+    /* If we haven't initialized, this is as much as can be validated. */
+    if (!ahci->hba_base) {
+        return;
+    }
+
+    hba_base = (uint64_t)qpci_config_readl(ahci->dev, PCI_BASE_ADDRESS_5);
+    hba_stored = (uint64_t)(uintptr_t)ahci->hba_base;
+    g_assert_cmphex(hba_base, ==, hba_stored);
+
+    g_assert_cmphex(ahci_rreg(ahci, AHCI_CAP), ==, ahci->cap);
+    g_assert_cmphex(ahci_rreg(ahci, AHCI_CAP2), ==, ahci->cap2);
+
+    for (i = 0; i < 32; i++) {
+        g_assert_cmphex(ahci_px_rreg(ahci, i, AHCI_PX_FB), ==,
+                        ahci->port[i].fb);
+        g_assert_cmphex(ahci_px_rreg(ahci, i, AHCI_PX_CLB), ==,
+                        ahci->port[i].clb);
+        for (j = 0; j < 32; j++) {
+            ahci_get_command_header(ahci, i, j, &cmd);
+            g_assert_cmphex(cmd.prdtl, ==, ahci->port[i].prdtl[j]);
+            g_assert_cmphex(cmd.ctba, ==, ahci->port[i].ctba[j]);
+        }
+    }
+}
+
+static void ahci_migrate(AHCIQState *from, AHCIQState *to, const char *uri)
+{
+    QOSState *tmp = to->parent;
+    QPCIDevice *dev = to->dev;
+    if (uri == NULL) {
+        uri = "tcp:127.0.0.1:1234";
+    }
+
+    /* context will be 'to' after completion. */
+    migrate(from->parent, to->parent, uri);
+
+    /* We'd like for the AHCIState objects to still point
+     * to information specific to its specific parent
+     * instance, but otherwise just inherit the new data. */
+    memcpy(to, from, sizeof(AHCIQState));
+    to->parent = tmp;
+    to->dev = dev;
+
+    tmp = from->parent;
+    dev = from->dev;
+    memset(from, 0x00, sizeof(AHCIQState));
+    from->parent = tmp;
+    from->dev = dev;
+
+    verify_state(to);
+}
+
 /*** Test Setup & Teardown ***/
 
 /**
@@ -146,6 +212,8 @@ static AHCIQState *ahci_boot(const char *cli, ...)
 static void ahci_shutdown(AHCIQState *ahci)
 {
     QOSState *qs = ahci->parent;
+
+    set_context(qs);
     ahci_clean_mem(ahci);
     free_ahci_device(ahci->dev);
     g_free(ahci);
@@ -806,7 +874,7 @@ static void ahci_test_io_rw_simple(AHCIQState *ahci, unsigned bufsize,
 
     /* Write some indicative pattern to our buffer. */
     generate_pattern(tx, bufsize, AHCI_SECTOR_SIZE);
-    memwrite(ptr, tx, bufsize);
+    bufwrite(ptr, tx, bufsize);
 
     /* Write this buffer to disk, then read it back to the DMA buffer. */
     ahci_guest_io(ahci, port, write_cmd, ptr, bufsize, sector);
@@ -814,7 +882,7 @@ static void ahci_test_io_rw_simple(AHCIQState *ahci, unsigned bufsize,
     ahci_guest_io(ahci, port, read_cmd, ptr, bufsize, sector);
 
     /*** Read back the Data ***/
-    memread(ptr, rx, bufsize);
+    bufread(ptr, rx, bufsize);
     g_assert_cmphex(memcmp(tx, rx, bufsize), ==, 0);
 
     ahci_free(ahci, ptr);
@@ -950,7 +1018,7 @@ static void test_dma_fragmented(void)
     /* Create a DMA buffer in guest memory, and write our pattern to it. */
     ptr = guest_alloc(ahci->parent->alloc, bufsize);
     g_assert(ptr);
-    memwrite(ptr, tx, bufsize);
+    bufwrite(ptr, tx, bufsize);
 
     cmd = ahci_command_create(CMD_WRITE_DMA);
     ahci_command_adjust(cmd, 0, ptr, bufsize, 32);
@@ -967,7 +1035,7 @@ static void test_dma_fragmented(void)
     g_free(cmd);
 
     /* Read back the guest's receive buffer into local memory */
-    memread(ptr, rx, bufsize);
+    bufread(ptr, rx, bufsize);
     guest_free(ahci->parent->alloc, ptr);
 
     g_assert_cmphex(memcmp(tx, rx, bufsize), ==, 0);
@@ -1003,7 +1071,7 @@ static void test_flush_retry(void)
                                 debug_path,
                                 tmp_path);
 
-    /* Issue Flush Command */
+    /* Issue Flush Command and wait for error */
     port = ahci_port_select(ahci);
     ahci_port_clear(ahci, port);
     cmd = ahci_command_create(CMD_FLUSH_CACHE);
@@ -1022,6 +1090,250 @@ static void test_flush_retry(void)
     ahci_shutdown(ahci);
 }
 
+/**
+ * Basic sanity test to boot a machine, find an AHCI device, and shutdown.
+ */
+static void test_migrate_sanity(void)
+{
+    AHCIQState *src, *dst;
+    const char *uri = "tcp:127.0.0.1:1234";
+
+    src = ahci_boot("-m 1024 -M q35 "
+                    "-hda %s ", tmp_path);
+    dst = ahci_boot("-m 1024 -M q35 "
+                    "-hda %s "
+                    "-incoming %s", tmp_path, uri);
+
+    ahci_migrate(src, dst, uri);
+
+    ahci_shutdown(src);
+    ahci_shutdown(dst);
+}
+
+/**
+ * DMA Migration test: Write a pattern, migrate, then read.
+ */
+static void test_migrate_dma(void)
+{
+    AHCIQState *src, *dst;
+    uint8_t px;
+    size_t bufsize = 4096;
+    unsigned char *tx = g_malloc(bufsize);
+    unsigned char *rx = g_malloc0(bufsize);
+    unsigned i;
+    const char *uri = "tcp:127.0.0.1:1234";
+
+    src = ahci_boot_and_enable("-m 1024 -M q35 "
+                               "-hda %s ", tmp_path);
+    dst = ahci_boot("-m 1024 -M q35 "
+                    "-hda %s "
+                    "-incoming %s", tmp_path, uri);
+
+    set_context(src->parent);
+
+    /* initialize */
+    px = ahci_port_select(src);
+    ahci_port_clear(src, px);
+
+    /* create pattern */
+    for (i = 0; i < bufsize; i++) {
+        tx[i] = (bufsize - i);
+    }
+
+    /* Write, migrate, then read. */
+    ahci_io(src, px, CMD_WRITE_DMA, tx, bufsize, 0);
+    ahci_migrate(src, dst, uri);
+    ahci_io(dst, px, CMD_READ_DMA, rx, bufsize, 0);
+
+    /* Verify pattern */
+    g_assert_cmphex(memcmp(tx, rx, bufsize), ==, 0);
+
+    ahci_shutdown(src);
+    ahci_shutdown(dst);
+    g_free(rx);
+    g_free(tx);
+}
+
+/**
+ * DMA Error Test
+ *
+ * Simulate an error on first write, Try to write a pattern,
+ * Confirm the VM has stopped, resume the VM, verify command
+ * has completed, then read back the data and verify.
+ */
+static void test_halted_dma(void)
+{
+    AHCIQState *ahci;
+    uint8_t port;
+    size_t bufsize = 4096;
+    unsigned char *tx = g_malloc(bufsize);
+    unsigned char *rx = g_malloc0(bufsize);
+    unsigned i;
+    uint64_t ptr;
+    AHCICommand *cmd;
+
+    prepare_blkdebug_script(debug_path, "write_aio");
+
+    ahci = ahci_boot_and_enable("-drive file=blkdebug:%s:%s,if=none,id=drive0,"
+                                "format=qcow2,cache=writeback,"
+                                "rerror=stop,werror=stop "
+                                "-M q35 "
+                                "-device ide-hd,drive=drive0 ",
+                                debug_path,
+                                tmp_path);
+
+    /* Initialize and prepare */
+    port = ahci_port_select(ahci);
+    ahci_port_clear(ahci, port);
+
+    for (i = 0; i < bufsize; i++) {
+        tx[i] = (bufsize - i);
+    }
+
+    /* create DMA source buffer and write pattern */
+    ptr = ahci_alloc(ahci, bufsize);
+    g_assert(ptr);
+    memwrite(ptr, tx, bufsize);
+
+    /* Attempt to write (and fail) */
+    cmd = ahci_guest_io_halt(ahci, port, CMD_WRITE_DMA,
+                             ptr, bufsize, 0);
+
+    /* Attempt to resume the command */
+    ahci_guest_io_resume(ahci, cmd);
+    ahci_free(ahci, ptr);
+
+    /* Read back and verify */
+    ahci_io(ahci, port, CMD_READ_DMA, rx, bufsize, 0);
+    g_assert_cmphex(memcmp(tx, rx, bufsize), ==, 0);
+
+    /* Cleanup and go home */
+    ahci_shutdown(ahci);
+    g_free(rx);
+    g_free(tx);
+}
+
+/**
+ * DMA Error Migration Test
+ *
+ * Simulate an error on first write, Try to write a pattern,
+ * Confirm the VM has stopped, migrate, resume the VM,
+ * verify command has completed, then read back the data and verify.
+ */
+static void test_migrate_halted_dma(void)
+{
+    AHCIQState *src, *dst;
+    uint8_t port;
+    size_t bufsize = 4096;
+    unsigned char *tx = g_malloc(bufsize);
+    unsigned char *rx = g_malloc0(bufsize);
+    unsigned i;
+    uint64_t ptr;
+    AHCICommand *cmd;
+    const char *uri = "tcp:127.0.0.1:1234";
+
+    prepare_blkdebug_script(debug_path, "write_aio");
+
+    src = ahci_boot_and_enable("-drive file=blkdebug:%s:%s,if=none,id=drive0,"
+                               "format=qcow2,cache=writeback,"
+                               "rerror=stop,werror=stop "
+                               "-M q35 "
+                               "-device ide-hd,drive=drive0 ",
+                               debug_path,
+                               tmp_path);
+
+    dst = ahci_boot("-drive file=%s,if=none,id=drive0,"
+                    "format=qcow2,cache=writeback,"
+                    "rerror=stop,werror=stop "
+                    "-M q35 "
+                    "-device ide-hd,drive=drive0 "
+                    "-incoming %s",
+                    tmp_path, uri);
+
+    set_context(src->parent);
+
+    /* Initialize and prepare */
+    port = ahci_port_select(src);
+    ahci_port_clear(src, port);
+
+    for (i = 0; i < bufsize; i++) {
+        tx[i] = (bufsize - i);
+    }
+
+    /* create DMA source buffer and write pattern */
+    ptr = ahci_alloc(src, bufsize);
+    g_assert(ptr);
+    memwrite(ptr, tx, bufsize);
+
+    /* Write, trigger the VM to stop, migrate, then resume. */
+    cmd = ahci_guest_io_halt(src, port, CMD_WRITE_DMA,
+                             ptr, bufsize, 0);
+    ahci_migrate(src, dst, uri);
+    ahci_guest_io_resume(dst, cmd);
+    ahci_free(dst, ptr);
+
+    /* Read back */
+    ahci_io(dst, port, CMD_READ_DMA, rx, bufsize, 0);
+
+    /* Verify TX and RX are identical */
+    g_assert_cmphex(memcmp(tx, rx, bufsize), ==, 0);
+
+    /* Cleanup and go home. */
+    ahci_shutdown(src);
+    ahci_shutdown(dst);
+    g_free(rx);
+    g_free(tx);
+}
+
+/**
+ * Migration test: Try to flush, migrate, then resume.
+ */
+static void test_flush_migrate(void)
+{
+    AHCIQState *src, *dst;
+    AHCICommand *cmd;
+    uint8_t px;
+    const char *s;
+    const char *uri = "tcp:127.0.0.1:1234";
+
+    prepare_blkdebug_script(debug_path, "flush_to_disk");
+
+    src = ahci_boot_and_enable("-drive file=blkdebug:%s:%s,if=none,id=drive0,"
+                               "cache=writeback,rerror=stop,werror=stop "
+                               "-M q35 "
+                               "-device ide-hd,drive=drive0 ",
+                               debug_path, tmp_path);
+    dst = ahci_boot("-drive file=%s,if=none,id=drive0,"
+                    "cache=writeback,rerror=stop,werror=stop "
+                    "-M q35 "
+                    "-device ide-hd,drive=drive0 "
+                    "-incoming %s", tmp_path, uri);
+
+    set_context(src->parent);
+
+    /* Issue Flush Command */
+    px = ahci_port_select(src);
+    ahci_port_clear(src, px);
+    cmd = ahci_command_create(CMD_FLUSH_CACHE);
+    ahci_command_commit(src, cmd, px);
+    ahci_command_issue_async(src, cmd);
+    qmp_eventwait("STOP");
+
+    /* Migrate over */
+    ahci_migrate(src, dst, uri);
+
+    /* Complete the command */
+    s = "{'execute':'cont' }";
+    qmp_async(s);
+    qmp_eventwait("RESUME");
+    ahci_command_wait(dst, cmd);
+    ahci_command_verify(dst, cmd);
+
+    ahci_command_free(cmd);
+    ahci_shutdown(src);
+    ahci_shutdown(dst);
+}
+
 /******************************************************************************/
 /* AHCI I/O Test Matrix Definitions                                           */
 
@@ -1270,6 +1582,12 @@ int main(int argc, char **argv)
 
     qtest_add_func("/ahci/flush/simple", test_flush);
     qtest_add_func("/ahci/flush/retry", test_flush_retry);
+    qtest_add_func("/ahci/flush/migrate", test_flush_migrate);
+
+    qtest_add_func("/ahci/migrate/sanity", test_migrate_sanity);
+    qtest_add_func("/ahci/migrate/dma/simple", test_migrate_dma);
+    qtest_add_func("/ahci/io/dma/lba28/retry", test_halted_dma);
+    qtest_add_func("/ahci/migrate/dma/halted", test_migrate_halted_dma);
 
     ret = g_test_run();
 
diff --git a/tests/libqos/ahci.c b/tests/libqos/ahci.c
index 843cf72..7e17bb6 100644
--- a/tests/libqos/ahci.c
+++ b/tests/libqos/ahci.c
@@ -566,6 +566,33 @@ inline unsigned size_to_prdtl(unsigned bytes, unsigned bytes_per_prd)
     return (bytes + bytes_per_prd - 1) / bytes_per_prd;
 }
 
+/* Issue a command, expecting it to fail and STOP the VM */
+AHCICommand *ahci_guest_io_halt(AHCIQState *ahci, uint8_t port,
+                                uint8_t ide_cmd, uint64_t buffer,
+                                size_t bufsize, uint64_t sector)
+{
+    AHCICommand *cmd;
+
+    cmd = ahci_command_create(ide_cmd);
+    ahci_command_adjust(cmd, sector, buffer, bufsize, 0);
+    ahci_command_commit(ahci, cmd, port);
+    ahci_command_issue_async(ahci, cmd);
+    qmp_eventwait("STOP");
+
+    return cmd;
+}
+
+/* Resume a previously failed command and verify/finalize */
+void ahci_guest_io_resume(AHCIQState *ahci, AHCICommand *cmd)
+{
+    /* Complete the command */
+    qmp_async("{'execute':'cont' }");
+    qmp_eventwait("RESUME");
+    ahci_command_wait(ahci, cmd);
+    ahci_command_verify(ahci, cmd);
+    ahci_command_free(cmd);
+}
+
 /* Given a guest buffer address, perform an IO operation */
 void ahci_guest_io(AHCIQState *ahci, uint8_t port, uint8_t ide_cmd,
                    uint64_t buffer, size_t bufsize, uint64_t sector)
@@ -623,15 +650,16 @@ void ahci_io(AHCIQState *ahci, uint8_t port, uint8_t ide_cmd,
     g_assert(props);
     ptr = ahci_alloc(ahci, bufsize);
     g_assert(ptr);
+    qmemset(ptr, 0x00, bufsize);
 
     if (props->write) {
-        memwrite(ptr, buffer, bufsize);
+        bufwrite(ptr, buffer, bufsize);
     }
 
     ahci_guest_io(ahci, port, ide_cmd, ptr, bufsize, sector);
 
     if (props->read) {
-        memread(ptr, buffer, bufsize);
+        bufread(ptr, buffer, bufsize);
     }
 
     ahci_free(ahci, ptr);
@@ -742,7 +770,7 @@ void ahci_command_set_offset(AHCICommand *cmd, uint64_t lba_sect)
     fis->lba_lo[1] = (lba_sect >> 8) & 0xFF;
     fis->lba_lo[2] = (lba_sect >> 16) & 0xFF;
     if (cmd->props->lba28) {
-        fis->device = (fis->device & 0xF0) || (lba_sect >> 24) & 0x0F;
+        fis->device = (fis->device & 0xF0) | ((lba_sect >> 24) & 0x0F);
     }
     fis->lba_hi[0] = (lba_sect >> 24) & 0xFF;
     fis->lba_hi[1] = (lba_sect >> 32) & 0xFF;
@@ -760,7 +788,9 @@ void ahci_command_set_sizes(AHCICommand *cmd, uint64_t xbytes,
     /* Each PRD can describe up to 4MiB, and must not be odd. */
     g_assert_cmphex(prd_size, <=, 4096 * 1024);
     g_assert_cmphex(prd_size & 0x01, ==, 0x00);
-    cmd->prd_size = prd_size;
+    if (prd_size) {
+        cmd->prd_size = prd_size;
+    }
     cmd->xbytes = xbytes;
     cmd->fis.count = (cmd->xbytes / AHCI_SECTOR_SIZE);
     cmd->header.prdtl = size_to_prdtl(cmd->xbytes, cmd->prd_size);
diff --git a/tests/libqos/ahci.h b/tests/libqos/ahci.h
index 40e8ca4..779e812 100644
--- a/tests/libqos/ahci.h
+++ b/tests/libqos/ahci.h
@@ -524,6 +524,9 @@ unsigned ahci_pick_cmd(AHCIQState *ahci, uint8_t port);
 unsigned size_to_prdtl(unsigned bytes, unsigned bytes_per_prd);
 void ahci_guest_io(AHCIQState *ahci, uint8_t port, uint8_t ide_cmd,
                    uint64_t gbuffer, size_t size, uint64_t sector);
+AHCICommand *ahci_guest_io_halt(AHCIQState *ahci, uint8_t port, uint8_t ide_cmd,
+                                uint64_t gbuffer, size_t size, uint64_t sector);
+void ahci_guest_io_resume(AHCIQState *ahci, AHCICommand *cmd);
 void ahci_io(AHCIQState *ahci, uint8_t port, uint8_t ide_cmd,
              void *buffer, size_t bufsize, uint64_t sector);
 
diff --git a/tests/libqos/libqos.c b/tests/libqos/libqos.c
index 7e72078..fce625b 100644
--- a/tests/libqos/libqos.c
+++ b/tests/libqos/libqos.c
@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <glib.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -62,6 +63,90 @@ void qtest_shutdown(QOSState *qs)
     g_free(qs);
 }
 
+void set_context(QOSState *s)
+{
+    global_qtest = s->qts;
+}
+
+static QDict *qmp_execute(const char *command)
+{
+    char *fmt;
+    QDict *rsp;
+
+    fmt = g_strdup_printf("{ 'execute': '%s' }", command);
+    rsp = qmp(fmt);
+    g_free(fmt);
+
+    return rsp;
+}
+
+void migrate(QOSState *from, QOSState *to, const char *uri)
+{
+    const char *st;
+    char *s;
+    QDict *rsp, *sub;
+    bool running;
+
+    set_context(from);
+
+    /* Is the machine currently running? */
+    rsp = qmp_execute("query-status");
+    g_assert(qdict_haskey(rsp, "return"));
+    sub = qdict_get_qdict(rsp, "return");
+    g_assert(qdict_haskey(sub, "running"));
+    running = qdict_get_bool(sub, "running");
+    QDECREF(rsp);
+
+    /* Issue the migrate command. */
+    s = g_strdup_printf("{ 'execute': 'migrate',"
+                        "'arguments': { 'uri': '%s' } }",
+                        uri);
+    rsp = qmp(s);
+    g_free(s);
+    g_assert(qdict_haskey(rsp, "return"));
+    QDECREF(rsp);
+
+    /* Wait for STOP event, but only if we were running: */
+    if (running) {
+        qmp_eventwait("STOP");
+    }
+
+    /* If we were running, we can wait for an event. */
+    if (running) {
+        migrate_allocator(from->alloc, to->alloc);
+        set_context(to);
+        qmp_eventwait("RESUME");
+        return;
+    }
+
+    /* Otherwise, we need to wait: poll until migration is completed. */
+    while (1) {
+        rsp = qmp_execute("query-migrate");
+        g_assert(qdict_haskey(rsp, "return"));
+        sub = qdict_get_qdict(rsp, "return");
+        g_assert(qdict_haskey(sub, "status"));
+        st = qdict_get_str(sub, "status");
+
+        /* "setup", "active", "completed", "failed", "cancelled" */
+        if (strcmp(st, "completed") == 0) {
+            QDECREF(rsp);
+            break;
+        }
+
+        if ((strcmp(st, "setup") == 0) || (strcmp(st, "active") == 0)) {
+            QDECREF(rsp);
+            g_usleep(5000);
+            continue;
+        }
+
+        fprintf(stderr, "Migration did not complete, status: %s\n", st);
+        g_assert_not_reached();
+    }
+
+    migrate_allocator(from->alloc, to->alloc);
+    set_context(to);
+}
+
 void mkimg(const char *file, const char *fmt, unsigned size_mb)
 {
     gchar *cli;
diff --git a/tests/libqos/libqos.h b/tests/libqos/libqos.h
index f57362b..e1f14ea 100644
--- a/tests/libqos/libqos.h
+++ b/tests/libqos/libqos.h
@@ -21,6 +21,8 @@ QOSState *qtest_boot(QOSOps *ops, const char *cmdline_fmt, ...);
 void qtest_shutdown(QOSState *qs);
 void mkimg(const char *file, const char *fmt, unsigned size_mb);
 void mkqcow2(const char *file, unsigned size_mb);
+void set_context(QOSState *s);
+void migrate(QOSState *from, QOSState *to, const char *uri);
 void prepare_blkdebug_script(const char *debug_fn, const char *event);
 
 static inline uint64_t qmalloc(QOSState *q, size_t bytes)
diff --git a/tests/libqos/malloc.c b/tests/libqos/malloc.c
index 67f3190..8276130 100644
--- a/tests/libqos/malloc.c
+++ b/tests/libqos/malloc.c
@@ -30,8 +30,8 @@ struct QGuestAllocator {
     uint64_t end;
     uint32_t page_size;
 
-    MemList used;
-    MemList free;
+    MemList *used;
+    MemList *free;
 };
 
 #define DEFAULT_PAGE_SIZE 4096
@@ -150,7 +150,7 @@ static uint64_t mlist_fulfill(QGuestAllocator *s, MemBlock *freenode,
     addr = freenode->addr;
     if (freenode->size == size) {
         /* re-use this freenode as our used node */
-        QTAILQ_REMOVE(&s->free, freenode, MLIST_ENTNAME);
+        QTAILQ_REMOVE(s->free, freenode, MLIST_ENTNAME);
         usednode = freenode;
     } else {
         /* adjust the free node and create a new used node */
@@ -159,7 +159,7 @@ static uint64_t mlist_fulfill(QGuestAllocator *s, MemBlock *freenode,
         usednode = mlist_new(addr, size);
     }
 
-    mlist_sort_insert(&s->used, usednode);
+    mlist_sort_insert(s->used, usednode);
     return addr;
 }
 
@@ -171,7 +171,7 @@ static void mlist_check(QGuestAllocator *s)
     uint64_t addr = s->start > 0 ? s->start - 1 : 0;
     uint64_t next = s->start;
 
-    QTAILQ_FOREACH(node, &s->free, MLIST_ENTNAME) {
+    QTAILQ_FOREACH(node, s->free, MLIST_ENTNAME) {
         g_assert_cmpint(node->addr, >, addr);
         g_assert_cmpint(node->addr, >=, next);
         addr = node->addr;
@@ -180,7 +180,7 @@ static void mlist_check(QGuestAllocator *s)
 
     addr = s->start > 0 ? s->start - 1 : 0;
     next = s->start;
-    QTAILQ_FOREACH(node, &s->used, MLIST_ENTNAME) {
+    QTAILQ_FOREACH(node, s->used, MLIST_ENTNAME) {
         g_assert_cmpint(node->addr, >, addr);
         g_assert_cmpint(node->addr, >=, next);
         addr = node->addr;
@@ -192,7 +192,7 @@ static uint64_t mlist_alloc(QGuestAllocator *s, uint64_t size)
 {
     MemBlock *node;
 
-    node = mlist_find_space(&s->free, size);
+    node = mlist_find_space(s->free, size);
     if (!node) {
         fprintf(stderr, "Out of guest memory.\n");
         g_assert_not_reached();
@@ -208,7 +208,7 @@ static void mlist_free(QGuestAllocator *s, uint64_t addr)
         return;
     }
 
-    node = mlist_find_key(&s->used, addr);
+    node = mlist_find_key(s->used, addr);
     if (!node) {
         fprintf(stderr, "Error: no record found for an allocation at "
                 "0x%016" PRIx64 ".\n",
@@ -217,9 +217,9 @@ static void mlist_free(QGuestAllocator *s, uint64_t addr)
     }
 
     /* Rip it out of the used list and re-insert back into the free list. */
-    QTAILQ_REMOVE(&s->used, node, MLIST_ENTNAME);
-    mlist_sort_insert(&s->free, node);
-    mlist_coalesce(&s->free, node);
+    QTAILQ_REMOVE(s->used, node, MLIST_ENTNAME);
+    mlist_sort_insert(s->free, node);
+    mlist_coalesce(s->free, node);
 }
 
 /*
@@ -233,7 +233,7 @@ void alloc_uninit(QGuestAllocator *allocator)
     QAllocOpts mask;
 
     /* Check for guest leaks, and destroy the list. */
-    QTAILQ_FOREACH_SAFE(node, &allocator->used, MLIST_ENTNAME, tmp) {
+    QTAILQ_FOREACH_SAFE(node, allocator->used, MLIST_ENTNAME, tmp) {
         if (allocator->opts & (ALLOC_LEAK_WARN | ALLOC_LEAK_ASSERT)) {
             fprintf(stderr, "guest malloc leak @ 0x%016" PRIx64 "; "
                     "size 0x%016" PRIx64 ".\n",
@@ -248,7 +248,7 @@ void alloc_uninit(QGuestAllocator *allocator)
     /* If we have previously asserted that there are no leaks, then there
      * should be only one node here with a specific address and size. */
     mask = ALLOC_LEAK_ASSERT | ALLOC_PARANOID;
-    QTAILQ_FOREACH_SAFE(node, &allocator->free, MLIST_ENTNAME, tmp) {
+    QTAILQ_FOREACH_SAFE(node, allocator->free, MLIST_ENTNAME, tmp) {
         if ((allocator->opts & mask) == mask) {
             if ((node->addr != allocator->start) ||
                 (node->size != allocator->end - allocator->start)) {
@@ -260,6 +260,8 @@ void alloc_uninit(QGuestAllocator *allocator)
         g_free(node);
     }
 
+    g_free(allocator->used);
+    g_free(allocator->free);
     g_free(allocator);
 }
 
@@ -297,11 +299,13 @@ QGuestAllocator *alloc_init(uint64_t start, uint64_t end)
     s->start = start;
     s->end = end;
 
-    QTAILQ_INIT(&s->used);
-    QTAILQ_INIT(&s->free);
+    s->used = g_malloc(sizeof(MemList));
+    s->free = g_malloc(sizeof(MemList));
+    QTAILQ_INIT(s->used);
+    QTAILQ_INIT(s->free);
 
     node = mlist_new(s->start, s->end - s->start);
-    QTAILQ_INSERT_HEAD(&s->free, node, MLIST_ENTNAME);
+    QTAILQ_INSERT_HEAD(s->free, node, MLIST_ENTNAME);
 
     s->page_size = DEFAULT_PAGE_SIZE;
 
@@ -319,7 +323,7 @@ QGuestAllocator *alloc_init_flags(QAllocOpts opts,
 void alloc_set_page_size(QGuestAllocator *allocator, size_t page_size)
 {
     /* Can't alter the page_size for an allocator in-use */
-    g_assert(QTAILQ_EMPTY(&allocator->used));
+    g_assert(QTAILQ_EMPTY(allocator->used));
 
     g_assert(is_power_of_2(page_size));
     allocator->page_size = page_size;
@@ -329,3 +333,39 @@ void alloc_set_flags(QGuestAllocator *allocator, QAllocOpts opts)
 {
     allocator->opts |= opts;
 }
+
+void migrate_allocator(QGuestAllocator *src,
+                       QGuestAllocator *dst)
+{
+    MemBlock *node, *tmp;
+    MemList *tmpused, *tmpfree;
+
+    /* The general memory layout should be equivalent,
+     * though opts can differ. */
+    g_assert_cmphex(src->start, ==, dst->start);
+    g_assert_cmphex(src->end, ==, dst->end);
+
+    /* Destroy (silently, regardless of options) the dest-list: */
+    QTAILQ_FOREACH_SAFE(node, dst->used, MLIST_ENTNAME, tmp) {
+        g_free(node);
+    }
+    QTAILQ_FOREACH_SAFE(node, dst->free, MLIST_ENTNAME, tmp) {
+        g_free(node);
+    }
+
+    tmpused = dst->used;
+    tmpfree = dst->free;
+
+    /* Inherit the lists of the source allocator: */
+    dst->used = src->used;
+    dst->free = src->free;
+
+    /* Source is now re-initialized, the source memory is 'invalid' now: */
+    src->used = tmpused;
+    src->free = tmpfree;
+    QTAILQ_INIT(src->used);
+    QTAILQ_INIT(src->free);
+    node = mlist_new(src->start, src->end - src->start);
+    QTAILQ_INSERT_HEAD(src->free, node, MLIST_ENTNAME);
+    return;
+}
diff --git a/tests/libqos/malloc.h b/tests/libqos/malloc.h
index 71ac407..0c6c9b7 100644
--- a/tests/libqos/malloc.h
+++ b/tests/libqos/malloc.h
@@ -31,6 +31,7 @@ void alloc_uninit(QGuestAllocator *allocator);
 /* Always returns page aligned values */
 uint64_t guest_alloc(QGuestAllocator *allocator, size_t size);
 void guest_free(QGuestAllocator *allocator, uint64_t addr);
+void migrate_allocator(QGuestAllocator *src, QGuestAllocator *dst);
 
 QGuestAllocator *alloc_init(uint64_t start, uint64_t end);
 QGuestAllocator *alloc_init_flags(QAllocOpts flags,
diff --git a/tests/libqtest.c b/tests/libqtest.c
index a525dc5..e5188e0 100644
--- a/tests/libqtest.c
+++ b/tests/libqtest.c
@@ -695,28 +695,55 @@ void qtest_add_data_func(const char *str, const void *data, void (*fn))
     g_free(path);
 }
 
+void qtest_bufwrite(QTestState *s, uint64_t addr, const void *data, size_t size)
+{
+    gchar *bdata;
+
+    bdata = g_base64_encode(data, size);
+    qtest_sendf(s, "b64write 0x%" PRIx64 " 0x%zx ", addr, size);
+    socket_send(s->fd, bdata, strlen(bdata));
+    socket_send(s->fd, "\n", 1);
+    qtest_rsp(s, 0);
+    g_free(bdata);
+}
+
+void qtest_bufread(QTestState *s, uint64_t addr, void *data, size_t size)
+{
+    gchar **args;
+    size_t len;
+
+    qtest_sendf(s, "b64read 0x%" PRIx64 " 0x%zx\n", addr, size);
+    args = qtest_rsp(s, 2);
+
+    g_base64_decode_inplace(args[1], &len);
+    if (size != len) {
+        fprintf(stderr, "bufread: asked for %zu bytes but decoded %zu\n",
+                size, len);
+        len = MIN(len, size);
+    }
+
+    memcpy(data, args[1], len);
+    g_strfreev(args);
+}
+
 void qtest_memwrite(QTestState *s, uint64_t addr, const void *data, size_t size)
 {
     const uint8_t *ptr = data;
     size_t i;
+    char *enc = g_malloc(2 * size + 1);
 
-    qtest_sendf(s, "write 0x%" PRIx64 " 0x%zx 0x", addr, size);
     for (i = 0; i < size; i++) {
-        qtest_sendf(s, "%02x", ptr[i]);
+        sprintf(&enc[i * 2], "%02x", ptr[i]);
     }
-    qtest_sendf(s, "\n");
+
+    qtest_sendf(s, "write 0x%" PRIx64 " 0x%zx 0x%s\n", addr, size, enc);
     qtest_rsp(s, 0);
+    g_free(enc);
 }
 
 void qtest_memset(QTestState *s, uint64_t addr, uint8_t pattern, size_t size)
 {
-    size_t i;
-
-    qtest_sendf(s, "write 0x%" PRIx64 " 0x%zx 0x", addr, size);
-    for (i = 0; i < size; i++) {
-        qtest_sendf(s, "%02x", pattern);
-    }
-    qtest_sendf(s, "\n");
+    qtest_sendf(s, "memset 0x%" PRIx64 " 0x%zx 0x%02x\n", addr, size, pattern);
     qtest_rsp(s, 0);
 }
 
diff --git a/tests/libqtest.h b/tests/libqtest.h
index 4b54b5d..ec42031 100644
--- a/tests/libqtest.h
+++ b/tests/libqtest.h
@@ -301,6 +301,17 @@ uint64_t qtest_readq(QTestState *s, uint64_t addr);
 void qtest_memread(QTestState *s, uint64_t addr, void *data, size_t size);
 
 /**
+ * qtest_bufread:
+ * @s: #QTestState instance to operate on.
+ * @addr: Guest address to read from.
+ * @data: Pointer to where memory contents will be stored.
+ * @size: Number of bytes to read.
+ *
+ * Read guest memory into a buffer and receive using a base64 encoding.
+ */
+void qtest_bufread(QTestState *s, uint64_t addr, void *data, size_t size);
+
+/**
  * qtest_memwrite:
  * @s: #QTestState instance to operate on.
  * @addr: Guest address to write to.
@@ -312,6 +323,18 @@ void qtest_memread(QTestState *s, uint64_t addr, void *data, size_t size);
 void qtest_memwrite(QTestState *s, uint64_t addr, const void *data, size_t size);
 
 /**
+ * qtest_bufwrite:
+ * @s: #QTestState instance to operate on.
+ * @addr: Guest address to write to.
+ * @data: Pointer to the bytes that will be written to guest memory.
+ * @size: Number of bytes to write.
+ *
+ * Write a buffer to guest memory and transmit using a base64 encoding.
+ */
+void qtest_bufwrite(QTestState *s, uint64_t addr,
+                    const void *data, size_t size);
+
+/**
  * qtest_memset:
  * @s: #QTestState instance to operate on.
  * @addr: Guest address to write to.
@@ -699,6 +722,19 @@ static inline void memread(uint64_t addr, void *data, size_t size)
 }
 
 /**
+ * bufread:
+ * @addr: Guest address to read from.
+ * @data: Pointer to where memory contents will be stored.
+ * @size: Number of bytes to read.
+ *
+ * Read guest memory into a buffer, receive using a base64 encoding.
+ */
+static inline void bufread(uint64_t addr, void *data, size_t size)
+{
+    qtest_bufread(global_qtest, addr, data, size);
+}
+
+/**
  * memwrite:
  * @addr: Guest address to write to.
  * @data: Pointer to the bytes that will be written to guest memory.
@@ -712,6 +748,19 @@ static inline void memwrite(uint64_t addr, const void *data, size_t size)
 }
 
 /**
+ * bufwrite:
+ * @addr: Guest address to write to.
+ * @data: Pointer to the bytes that will be written to guest memory.
+ * @size: Number of bytes to write.
+ *
+ * Write a buffer to guest memory, transmit using a base64 encoding.
+ */
+static inline void bufwrite(uint64_t addr, const void *data, size_t size)
+{
+    qtest_bufwrite(global_qtest, addr, data, size);
+}
+
+/**
  * qmemset:
  * @addr: Guest address to write to.
  * @patt: Byte pattern to fill the guest memory region with.