vga: bugfixes for qxl, cirrus, ati.

vga: add "-vga help" support.
 vga: move i2c-ddc to display.
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Merge remote-tracking branch 'remotes/kraxel/tags/vga-20190507-pull-request' into staging

vga: bugfixes for qxl, cirrus, ati.
vga: add "-vga help" support.
vga: move i2c-ddc to display.

# gpg: Signature made Tue 07 May 2019 09:19:32 BST
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/vga-20190507-pull-request:
  i2c-ddc: move it to hw/display
  ati-vga: Fix check for blt outside vram
  qxl: avoid unaligned pointer reads/writes
  vl: add -vga help support
  vl: constify VGAInterfaceInfo
  hw/display/cirrus_vga: Remove unused include
  hw/display/cirrus_vga: Update the documentation URL
  qxl: check release info object

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

hw/display/Kconfig

@@ -1,3 +1,8 @@
+config DDC
+    bool
+    depends on I2C
+    select EDID
+
 config EDID
     bool
 

hw/display/Makefile.objs

@@ -1,3 +1,4 @@
+common-obj-$(CONFIG_DDC) += i2c-ddc.o
 common-obj-$(CONFIG_EDID) += edid-generate.o edid-region.o
 
 common-obj-$(CONFIG_FW_CFG_DMA) += ramfb.o

hw/display/ati_2d.c

@@ -79,10 +79,10 @@ void ati_2d_blt(ATIVGAState *s)
                 s->regs.dst_width, s->regs.dst_height);
         end = s->vga.vram_ptr + s->vga.vram_size;
         if (src_bits >= end || dst_bits >= end ||
-            src_bits + (s->regs.src_y + s->regs.dst_height) * src_stride +
+            src_bits + s->regs.src_x + (s->regs.src_y + s->regs.dst_height) *
-            s->regs.src_x >= end ||
+            src_stride * sizeof(uint32_t) >= end ||
-            dst_bits + (s->regs.dst_y + s->regs.dst_height) * dst_stride +
+            dst_bits + s->regs.dst_x + (s->regs.dst_y + s->regs.dst_height) *
-            s->regs.dst_x >= end) {
+            dst_stride * sizeof(uint32_t) >= end) {
             qemu_log_mask(LOG_UNIMP, "blt outside vram not implemented\n");
             return;
         }
@@ -140,8 +140,8 @@ void ati_2d_blt(ATIVGAState *s)
                 filler);
         end = s->vga.vram_ptr + s->vga.vram_size;
         if (dst_bits >= end ||
-            dst_bits + (s->regs.dst_y + s->regs.dst_height) * dst_stride +
+            dst_bits + s->regs.dst_x + (s->regs.dst_y + s->regs.dst_height) *
-            s->regs.dst_x >= end) {
+            dst_stride * sizeof(uint32_t) >= end) {
             qemu_log_mask(LOG_UNIMP, "blt outside vram not implemented\n");
             return;
         }

hw/display/cirrus_vga.c

@@ -23,8 +23,13 @@
  * THE SOFTWARE.
  */
 /*
- * Reference: Finn Thogersons' VGADOC4b
+ * Reference: Finn Thogersons' VGADOC4b:
- *   available at http://home.worldonline.dk/~finth/
+ *
+ *  http://web.archive.org/web/20021019054927/http://home.worldonline.dk/finth/
+ *
+ * VGADOC4b.ZIP content available at:
+ *
+ *  https://pdos.csail.mit.edu/6.828/2005/readings/hardware/vgadoc
  */
 #include "qemu/osdep.h"
 #include "qemu/units.h"
@@ -33,7 +38,6 @@
 #include "hw/hw.h"
 #include "hw/pci/pci.h"
 #include "ui/pixel_ops.h"
-#include "hw/loader.h"
 #include "cirrus_vga_internal.h"
 
 /*

hw/display/i2c-ddc.c

@@ -20,7 +20,7 @@
 #include "qemu-common.h"
 #include "qemu/log.h"
 #include "hw/i2c/i2c.h"
-#include "hw/i2c/i2c-ddc.h"
+#include "hw/display/i2c-ddc.h"
 
 #ifndef DEBUG_I2CDDC
 #define DEBUG_I2CDDC 0

hw/display/qxl.c

@@ -33,24 +33,6 @@
 
 #include "qxl.h"
 
-/*
- * NOTE: SPICE_RING_PROD_ITEM accesses memory on the pci bar and as
- * such can be changed by the guest, so to avoid a guest trigerrable
- * abort we just qxl_set_guest_bug and set the return to NULL. Still
- * it may happen as a result of emulator bug as well.
- */
-#undef SPICE_RING_PROD_ITEM
-#define SPICE_RING_PROD_ITEM(qxl, r, ret) {                             \
-        uint32_t prod = (r)->prod & SPICE_RING_INDEX_MASK(r);           \
-        if (prod >= ARRAY_SIZE((r)->items)) {                           \
-            qxl_set_guest_bug(qxl, "SPICE_RING_PROD_ITEM indices mismatch " \
-                          "%u >= %zu", prod, ARRAY_SIZE((r)->items));   \
-            ret = NULL;                                                 \
-        } else {                                                        \
-            ret = &(r)->items[prod].el;                                 \
-        }                                                               \
-    }
-
 #undef SPICE_RING_CONS_ITEM
 #define SPICE_RING_CONS_ITEM(qxl, r, ret) {                             \
         uint32_t cons = (r)->cons & SPICE_RING_INDEX_MASK(r);           \
@@ -414,7 +396,8 @@ static void init_qxl_rom(PCIQXLDevice *d)
 static void init_qxl_ram(PCIQXLDevice *d)
 {
     uint8_t *buf;
-    uint64_t *item;
+    uint32_t prod;
+    QXLReleaseRing *ring;
 
     buf = d->vga.vram_ptr;
     d->ram = (QXLRam *)(buf + le32_to_cpu(d->shadow_rom.ram_header_offset));
@@ -426,9 +409,12 @@ static void init_qxl_ram(PCIQXLDevice *d)
     SPICE_RING_INIT(&d->ram->cmd_ring);
     SPICE_RING_INIT(&d->ram->cursor_ring);
     SPICE_RING_INIT(&d->ram->release_ring);
-    SPICE_RING_PROD_ITEM(d, &d->ram->release_ring, item);
+
-    assert(item);
+    ring = &d->ram->release_ring;
-    *item = 0;
+    prod = ring->prod & SPICE_RING_INDEX_MASK(ring);
+    assert(prod < ARRAY_SIZE(ring->items));
+    ring->items[prod].el = 0;
+
     qxl_ring_set_dirty(d);
 }
 
@@ -732,7 +718,7 @@ static int interface_req_cmd_notification(QXLInstance *sin)
 static inline void qxl_push_free_res(PCIQXLDevice *d, int flush)
 {
     QXLReleaseRing *ring = &d->ram->release_ring;
-    uint64_t *item;
+    uint32_t prod;
     int notify;
 
 #define QXL_FREE_BUNCH_SIZE 32
@@ -759,11 +745,15 @@ static inline void qxl_push_free_res(PCIQXLDevice *d, int flush)
     if (notify) {
         qxl_send_events(d, QXL_INTERRUPT_DISPLAY);
     }
-    SPICE_RING_PROD_ITEM(d, ring, item);
+
-    if (!item) {
+    ring = &d->ram->release_ring;
+    prod = ring->prod & SPICE_RING_INDEX_MASK(ring);
+    if (prod >= ARRAY_SIZE(ring->items)) {
+        qxl_set_guest_bug(d, "SPICE_RING_PROD_ITEM indices mismatch "
+                          "%u >= %zu", prod, ARRAY_SIZE(ring->items));
         return;
     }
-    *item = 0;
+    ring->items[prod].el = 0;
     d->num_free_res = 0;
     d->last_release = NULL;
     qxl_ring_set_dirty(d);
@@ -775,8 +765,12 @@ static void interface_release_resource(QXLInstance *sin,
 {
     PCIQXLDevice *qxl = container_of(sin, PCIQXLDevice, ssd.qxl);
     QXLReleaseRing *ring;
-    uint64_t *item, id;
+    uint32_t prod;
+    uint64_t id;
 
+    if (!ext.info) {
+        return;
+    }
     if (ext.group_id == MEMSLOT_GROUP_HOST) {
         /* host group -> vga mode update request */
         QXLCommandExt *cmdext = (void *)(intptr_t)(ext.info->id);
@@ -792,16 +786,18 @@ static void interface_release_resource(QXLInstance *sin,
      * pci bar 0, $command.release_info
      */
     ring = &qxl->ram->release_ring;
-    SPICE_RING_PROD_ITEM(qxl, ring, item);
+    prod = ring->prod & SPICE_RING_INDEX_MASK(ring);
-    if (!item) {
+    if (prod >= ARRAY_SIZE(ring->items)) {
+        qxl_set_guest_bug(qxl, "SPICE_RING_PROD_ITEM indices mismatch "
+                          "%u >= %zu", prod, ARRAY_SIZE(ring->items));
         return;
     }
-    if (*item == 0) {
+    if (ring->items[prod].el == 0) {
         /* stick head into the ring */
         id = ext.info->id;
         ext.info->next = 0;
         qxl_ram_set_dirty(qxl, &ext.info->next);
-        *item = id;
+        ring->items[prod].el = id;
         qxl_ring_set_dirty(qxl);
     } else {
         /* append item to the list */

hw/display/sii9022.c

@@ -16,7 +16,7 @@
 #include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "hw/i2c/i2c.h"
-#include "hw/i2c/i2c-ddc.h"
+#include "hw/display/i2c-ddc.h"
 #include "trace.h"
 
 #define SII9022_SYS_CTRL_DATA 0x1a

hw/display/sm501.c

@@ -35,7 +35,7 @@
 #include "hw/sysbus.h"
 #include "hw/pci/pci.h"
 #include "hw/i2c/i2c.h"
-#include "hw/i2c/i2c-ddc.h"
+#include "hw/display/i2c-ddc.h"
 #include "qemu/range.h"
 #include "ui/pixel_ops.h"
 #include "qemu/bswap.h"

hw/i2c/Kconfig

@@ -5,11 +5,6 @@ config SMBUS_EEPROM
     bool
     depends on I2C
 
-config DDC
-    bool
-    depends on I2C
-    select EDID
-
 config VERSATILE_I2C
     bool
     select I2C

hw/i2c/Makefile.objs

@@ -1,6 +1,5 @@
 common-obj-$(CONFIG_I2C) += core.o smbus_slave.o smbus_master.o
 common-obj-$(CONFIG_SMBUS_EEPROM) += smbus_eeprom.o
-common-obj-$(CONFIG_DDC) += i2c-ddc.o
 common-obj-$(CONFIG_VERSATILE_I2C) += versatile_i2c.o
 common-obj-$(CONFIG_ACPI_X86_ICH) += smbus_ich9.o
 common-obj-$(CONFIG_ACPI_SMBUS) += pm_smbus.o

include/hw/display/xlnx_dp.h

@@ -27,7 +27,7 @@
 #include "hw/misc/auxbus.h"
 #include "hw/i2c/i2c.h"
 #include "hw/display/dpcd.h"
-#include "hw/i2c/i2c-ddc.h"
+#include "hw/display/i2c-ddc.h"
 #include "qemu/fifo8.h"
 #include "qemu/units.h"
 #include "hw/dma/xlnx_dpdma.h"

vl.c

@@ -2015,7 +2015,7 @@ typedef struct VGAInterfaceInfo {
     const char *class_names[2];
 } VGAInterfaceInfo;
 
-static VGAInterfaceInfo vga_interfaces[VGA_TYPE_MAX] = {
+static const VGAInterfaceInfo vga_interfaces[VGA_TYPE_MAX] = {
     [VGA_NONE] = {
         .opt_name = "none",
     },
@@ -2061,7 +2061,7 @@ static VGAInterfaceInfo vga_interfaces[VGA_TYPE_MAX] = {
 
 static bool vga_interface_available(VGAInterfaceType t)
 {
-    VGAInterfaceInfo *ti = &vga_interfaces[t];
+    const VGAInterfaceInfo *ti = &vga_interfaces[t];
 
     assert(t < VGA_TYPE_MAX);
     return !ti->class_names[0] ||
@@ -2069,14 +2069,42 @@ static bool vga_interface_available(VGAInterfaceType t)
            object_class_by_name(ti->class_names[1]);
 }
 
-static void select_vgahw(const char *p)
+static const char *
+get_default_vga_model(const MachineClass *machine_class)
+{
+    if (machine_class->default_display) {
+        return machine_class->default_display;
+    } else if (vga_interface_available(VGA_CIRRUS)) {
+        return "cirrus";
+    } else if (vga_interface_available(VGA_STD)) {
+        return "std";
+    }
+
+    return NULL;
+}
+
+static void select_vgahw(const MachineClass *machine_class, const char *p)
 {
     const char *opts;
     int t;
 
+    if (g_str_equal(p, "help")) {
+        const char *def = get_default_vga_model(machine_class);
+
+        for (t = 0; t < VGA_TYPE_MAX; t++) {
+            const VGAInterfaceInfo *ti = &vga_interfaces[t];
+
+            if (vga_interface_available(t) && ti->opt_name) {
+                printf("%-20s %s%s\n", ti->opt_name, ti->name ?: "",
+                       g_str_equal(ti->opt_name, def) ? " (default)" : "");
+            }
+        }
+        exit(0);
+    }
+
     assert(vga_interface_type == VGA_NONE);
     for (t = 0; t < VGA_TYPE_MAX; t++) {
-        VGAInterfaceInfo *ti = &vga_interfaces[t];
+        const VGAInterfaceInfo *ti = &vga_interfaces[t];
         if (ti->opt_name && strstart(p, ti->opt_name, &opts)) {
             if (!vga_interface_available(t)) {
                 error_report("%s not available", ti->name);
@@ -4424,16 +4452,10 @@ int main(int argc, char **argv, char **envp)
 
     /* If no default VGA is requested, the default is "none".  */
     if (default_vga) {
-        if (machine_class->default_display) {
+        vga_model = get_default_vga_model(machine_class);
-            vga_model = machine_class->default_display;
-        } else if (vga_interface_available(VGA_CIRRUS)) {
-            vga_model = "cirrus";
-        } else if (vga_interface_available(VGA_STD)) {
-            vga_model = "std";
-        }
     }
     if (vga_model) {
-        select_vgahw(vga_model);
+        select_vgahw(machine_class, vga_model);
     }
 
     if (watchdog) {