hw/qxl: support client monitor configuration via device

Until now we used only the agent to change the monitor count and each
monitor resolution. This patch introduces the qemu part of using the
device as the mediator instead of the agent via virtio-serial.

Spice (>=0.11.5) calls the new QXLInterface::client_monitors_config,
which returns wether the interrupt is enabled, and if so and given a non
NULL monitors config will
generate an interrupt QXL_INTERRUPT_CLIENT_MONITORS_CONFIG with crc
checksum for the guest to verify a second call hasn't interfered.

The maximal number of monitors is limited on the QXLRom to 64.

Signed-off-by: Alon Levy <alevy@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

configure

@@ -2709,6 +2709,9 @@ EOF
     if $pkg_config --atleast-version=0.12.0 spice-protocol >/dev/null 2>&1; then
         spice_qxl_io_monitors_config_async="yes"
     fi
+    if $pkg_config --atleast-version=0.12.2 spice-protocol > /dev/null 2>&1; then
+        spice_qxl_client_monitors_config="yes"
+    fi
   else
     if test "$spice" = "yes" ; then
       feature_not_found "spice"
@@ -3456,6 +3459,10 @@ if test "$spice_qxl_io_monitors_config_async" = "yes" ; then
   echo "CONFIG_QXL_IO_MONITORS_CONFIG_ASYNC=y" >> $config_host_mak
 fi
 
+if test "$spice_qxl_client_monitors_config" = "yes" ; then
+  echo "CONFIG_QXL_CLIENT_MONITORS_CONFIG=y" >> $config_host_mak
+fi
+
 if test "$smartcard" = "yes" ; then
   echo "CONFIG_SMARTCARD=y" >> $config_host_mak
 fi

hw/qxl.c

@@ -18,6 +18,8 @@
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <zlib.h>
+
 #include "qemu-common.h"
 #include "qemu-timer.h"
 #include "qemu-queue.h"
@@ -971,6 +973,79 @@ static void interface_set_client_capabilities(QXLInstance *sin,
 
 #endif
 
+#if defined(CONFIG_QXL_CLIENT_MONITORS_CONFIG) \
+    && SPICE_SERVER_VERSION >= 0x000b05
+
+static uint32_t qxl_crc32(const uint8_t *p, unsigned len)
+{
+    /*
+     * zlib xors the seed with 0xffffffff, and xors the result
+     * again with 0xffffffff; Both are not done with linux's crc32,
+     * which we want to be compatible with, so undo that.
+     */
+    return crc32(0xffffffff, p, len) ^ 0xffffffff;
+}
+
+/* called from main context only */
+static int interface_client_monitors_config(QXLInstance *sin,
+                                        VDAgentMonitorsConfig *monitors_config)
+{
+    PCIQXLDevice *qxl = container_of(sin, PCIQXLDevice, ssd.qxl);
+    QXLRom *rom = memory_region_get_ram_ptr(&qxl->rom_bar);
+    int i;
+
+    /*
+     * Older windows drivers set int_mask to 0 when their ISR is called,
+     * then later set it to ~0. So it doesn't relate to the actual interrupts
+     * handled. However, they are old, so clearly they don't support this
+     * interrupt
+     */
+    if (qxl->ram->int_mask == 0 || qxl->ram->int_mask == ~0 ||
+        !(qxl->ram->int_mask & QXL_INTERRUPT_CLIENT_MONITORS_CONFIG)) {
+        trace_qxl_client_monitors_config_unsupported_by_guest(qxl->id,
+                                                            qxl->ram->int_mask,
+                                                            monitors_config);
+        return 0;
+    }
+    if (!monitors_config) {
+        return 1;
+    }
+    memset(&rom->client_monitors_config, 0,
+           sizeof(rom->client_monitors_config));
+    rom->client_monitors_config.count = monitors_config->num_of_monitors;
+    /* monitors_config->flags ignored */
+    if (rom->client_monitors_config.count >=
+            ARRAY_SIZE(rom->client_monitors_config.heads)) {
+        trace_qxl_client_monitors_config_capped(qxl->id,
+                                monitors_config->num_of_monitors,
+                                ARRAY_SIZE(rom->client_monitors_config.heads));
+        rom->client_monitors_config.count =
+            ARRAY_SIZE(rom->client_monitors_config.heads);
+    }
+    for (i = 0 ; i < rom->client_monitors_config.count ; ++i) {
+        VDAgentMonConfig *monitor = &monitors_config->monitors[i];
+        QXLURect *rect = &rom->client_monitors_config.heads[i];
+        /* monitor->depth ignored */
+        rect->left = monitor->x;
+        rect->top = monitor->y;
+        rect->right = monitor->x + monitor->width;
+        rect->bottom = monitor->y + monitor->height;
+    }
+    rom->client_monitors_config_crc = qxl_crc32(
+            (const uint8_t *)&rom->client_monitors_config,
+            sizeof(rom->client_monitors_config));
+    trace_qxl_client_monitors_config_crc(qxl->id,
+            sizeof(rom->client_monitors_config),
+            rom->client_monitors_config_crc);
+
+    trace_qxl_interrupt_client_monitors_config(qxl->id,
+                        rom->client_monitors_config.count,
+                        rom->client_monitors_config.heads);
+    qxl_send_events(qxl, QXL_INTERRUPT_CLIENT_MONITORS_CONFIG);
+    return 1;
+}
+#endif
+
 static const QXLInterface qxl_interface = {
     .base.type               = SPICE_INTERFACE_QXL,
     .base.description        = "qxl gpu",
@@ -995,6 +1070,10 @@ static const QXLInterface qxl_interface = {
 #if SPICE_SERVER_VERSION >= 0x000b04
     .set_client_capabilities = interface_set_client_capabilities,
 #endif
+#if SPICE_SERVER_VERSION >= 0x000b05 && \
+    defined(CONFIG_QXL_CLIENT_MONITORS_CONFIG)
+    .client_monitors_config = interface_client_monitors_config,
+#endif
 };
 
 static void qxl_enter_vga_mode(PCIQXLDevice *d)

trace-events

@@ -932,7 +932,7 @@ qxl_interface_update_area_complete_rest(int qid, uint32_t num_updated_rects) "%d
 qxl_interface_update_area_complete_overflow(int qid, int max) "%d max=%d"
 qxl_interface_update_area_complete_schedule_bh(int qid, uint32_t num_dirty) "%d #dirty=%d"
 qxl_io_destroy_primary_ignored(int qid, const char *mode) "%d %s"
-qxl_io_log(int qid, const uint8_t *str) "%d %s"
+qxl_io_log(int qid, const uint8_t *log_buf) "%d %s"
 qxl_io_read_unexpected(int qid) "%d"
 qxl_io_unexpected_vga_mode(int qid, uint64_t addr, uint64_t val, const char *desc) "%d 0x%"PRIx64"=%"PRIu64" (%s)"
 qxl_io_write(int qid, const char *mode, uint64_t addr, uint64_t val, unsigned size, int async) "%d %s addr=%"PRIu64 " val=%"PRIu64" size=%u async=%d"
@@ -976,6 +976,10 @@ qxl_spice_update_area_rest(int qid, uint32_t num_dirty_rects, uint32_t clear_dir
 qxl_surfaces_dirty(int qid, int surface, int offset, int size) "%d surface=%d offset=%d size=%d"
 qxl_send_events(int qid, uint32_t events) "%d %d"
 qxl_set_guest_bug(int qid) "%d"
+qxl_interrupt_client_monitors_config(int qid, int num_heads, void *heads) "%d %d %p"
+qxl_client_monitors_config_unsupported_by_guest(int qid, uint32_t int_mask, void *client_monitors_config) "%d %X %p"
+qxl_client_monitors_config_capped(int qid, int requested, int limit) "%d %d %d"
+qxl_client_monitors_config_crc(int qid, unsigned size, uint32_t crc32) "%d %u %u"
 
 # hw/qxl-render.c
 qxl_render_blit_guest_primary_initialized(void) ""