vo_gpu: vulkan: initial implementation

This time based on ra/vo_gpu. 2017 is the year of the vulkan desktop!

Current problems / limitations / improvement opportunities:

1. The swapchain/flipping code violates the vulkan spec, by assuming
   that the presentation queue will be bounded (in cases where rendering
   is significantly faster than vsync). But apparently, there's simply
   no better way to do this right now, to the point where even the
   stupid cube.c examples from LunarG etc. do it wrong.
   (cf. https://github.com/KhronosGroup/Vulkan-Docs/issues/370)

2. The memory allocator could be improved. (This is a universal
   constant)

3. Could explore using push descriptors instead of descriptor sets,
   especially since we expect to switch descriptors semi-often for some
   passes (like interpolation). Probably won't make a difference, but
   the synchronization overhead might be a factor. Who knows.

4. Parallelism across frames / async transfer is not well-defined, we
   either need to use a better semaphore / command buffer strategy or a
   resource pooling layer to safely handle cross-frame parallelism.
   (That said, I gave resource pooling a try and was not happy with the
   result at all - so I'm still exploring the semaphore strategy)

5. We aggressively use pipeline barriers where events would offer a much
   more fine-grained synchronization mechanism. As a result of this, we
   might be suffering from GPU bubbles due to too-short dependencies on
   objects. (That said, I'm also exploring the use of semaphores as a an
   ordering tactic which would allow cross-frame time slicing in theory)

Some minor changes to the vo_gpu and infrastructure, but nothing
consequential.

NOTE: For safety, all use of asynchronous commands / multiple command
pools is currently disabled completely. There are some left-over relics
of this in the code (e.g. the distinction between dev_poll and
pool_poll), but that is kept in place mostly because this will be
re-extended in the future (vulkan rev 2).

The queue count is also currently capped to 1, because of the lack of
cross-frame semaphores means we need the implicit synchronization from
the same-queue semantics to guarantee a correct result.

1 files changed, 726 insertions, 0 deletions

diff --git a/video/out/vulkan/utils.c b/video/out/vulkan/utils.c
new file mode 100644
index 0000000000..43e446bc36
--- /dev/null
+++ b/video/out/vulkan/utils.c
@@ -0,0 +1,726 @@
+#include <libavutil/macros.h>
+
+#include "utils.h"
+#include "malloc.h"
+
+const char* vk_err(VkResult res)
+{
+    switch (res) {
+    // These are technically success codes, but include them nonetheless
+    case VK_SUCCESS:     return "VK_SUCCESS";
+    case VK_NOT_READY:   return "VK_NOT_READY";
+    case VK_TIMEOUT:     return "VK_TIMEOUT";
+    case VK_EVENT_SET:   return "VK_EVENT_SET";
+    case VK_EVENT_RESET: return "VK_EVENT_RESET";
+    case VK_INCOMPLETE:  return "VK_INCOMPLETE";
+    case VK_SUBOPTIMAL_KHR: return "VK_SUBOPTIMAL_KHR";
+
+    // Actual error codes
+    case VK_ERROR_OUT_OF_HOST_MEMORY:    return "VK_ERROR_OUT_OF_HOST_MEMORY";
+    case VK_ERROR_OUT_OF_DEVICE_MEMORY:  return "VK_ERROR_OUT_OF_DEVICE_MEMORY";
+    case VK_ERROR_INITIALIZATION_FAILED: return "VK_ERROR_INITIALIZATION_FAILED";
+    case VK_ERROR_DEVICE_LOST:           return "VK_ERROR_DEVICE_LOST";
+    case VK_ERROR_MEMORY_MAP_FAILED:     return "VK_ERROR_MEMORY_MAP_FAILED";
+    case VK_ERROR_LAYER_NOT_PRESENT:     return "VK_ERROR_LAYER_NOT_PRESENT";
+    case VK_ERROR_EXTENSION_NOT_PRESENT: return "VK_ERROR_EXTENSION_NOT_PRESENT";
+    case VK_ERROR_FEATURE_NOT_PRESENT:   return "VK_ERROR_FEATURE_NOT_PRESENT";
+    case VK_ERROR_INCOMPATIBLE_DRIVER:   return "VK_ERROR_INCOMPATIBLE_DRIVER";
+    case VK_ERROR_TOO_MANY_OBJECTS:      return "VK_ERROR_TOO_MANY_OBJECTS";
+    case VK_ERROR_FORMAT_NOT_SUPPORTED:  return "VK_ERROR_FORMAT_NOT_SUPPORTED";
+    case VK_ERROR_FRAGMENTED_POOL:       return "VK_ERROR_FRAGMENTED_POOL";
+    case VK_ERROR_INVALID_SHADER_NV:     return "VK_ERROR_INVALID_SHADER_NV";
+    case VK_ERROR_OUT_OF_DATE_KHR:       return "VK_ERROR_OUT_OF_DATE_KHR";
+    case VK_ERROR_SURFACE_LOST_KHR:      return "VK_ERROR_SURFACE_LOST_KHR";
+    }
+
+    return "Unknown error!";
+}
+
+static const char* vk_dbg_type(VkDebugReportObjectTypeEXT type)
+{
+    switch (type) {
+    case VK_DEBUG_REPORT_OBJECT_TYPE_INSTANCE_EXT:
+        return "VkInstance";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_PHYSICAL_DEVICE_EXT:
+        return "VkPhysicalDevice";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_EXT:
+        return "VkDevice";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_QUEUE_EXT:
+        return "VkQueue";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_SEMAPHORE_EXT:
+        return "VkSemaphore";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_COMMAND_BUFFER_EXT:
+        return "VkCommandBuffer";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_FENCE_EXT:
+        return "VkFence";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_MEMORY_EXT:
+        return "VkDeviceMemory";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_BUFFER_EXT:
+        return "VkBuffer";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_IMAGE_EXT:
+        return "VkImage";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_EVENT_EXT:
+        return "VkEvent";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_QUERY_POOL_EXT:
+        return "VkQueryPool";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_BUFFER_VIEW_EXT:
+        return "VkBufferView";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_IMAGE_VIEW_EXT:
+        return "VkImageView";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_SHADER_MODULE_EXT:
+        return "VkShaderModule";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_PIPELINE_CACHE_EXT:
+        return "VkPipelineCache";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_PIPELINE_LAYOUT_EXT:
+        return "VkPipelineLayout";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_RENDER_PASS_EXT:
+        return "VkRenderPass";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_PIPELINE_EXT:
+        return "VkPipeline";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_SET_LAYOUT_EXT:
+        return "VkDescriptorSetLayout";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_SAMPLER_EXT:
+        return "VkSampler";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_POOL_EXT:
+        return "VkDescriptorPool";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_SET_EXT:
+        return "VkDescriptorSet";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_FRAMEBUFFER_EXT:
+        return "VkFramebuffer";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_COMMAND_POOL_EXT:
+        return "VkCommandPool";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_SURFACE_KHR_EXT:
+        return "VkSurfaceKHR";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_SWAPCHAIN_KHR_EXT:
+        return "VkSwapchainKHR";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_DEBUG_REPORT_EXT:
+        return "VkDebugReportCallbackEXT";
+    case VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT:
+    default:
+        return "unknown object";
+    }
+}
+
+static VkBool32 vk_dbg_callback(VkDebugReportFlagsEXT flags,
+                                VkDebugReportObjectTypeEXT objType,
+                                uint64_t obj, size_t loc, int32_t msgCode,
+                                const char *layer, const char *msg, void *priv)
+{
+    struct mpvk_ctx *vk = priv;
+    int lev = MSGL_V;
+
+    switch (flags) {
+    case VK_DEBUG_REPORT_ERROR_BIT_EXT:               lev = MSGL_ERR;   break;
+    case VK_DEBUG_REPORT_WARNING_BIT_EXT:             lev = MSGL_WARN;  break;
+    case VK_DEBUG_REPORT_INFORMATION_BIT_EXT:         lev = MSGL_TRACE; break;
+    case VK_DEBUG_REPORT_PERFORMANCE_WARNING_BIT_EXT: lev = MSGL_WARN;  break;
+    case VK_DEBUG_REPORT_DEBUG_BIT_EXT:               lev = MSGL_DEBUG; break;
+    };
+
+    MP_MSG(vk, lev, "vk [%s] %d: %s (obj 0x%llx (%s), loc 0x%zx)\n",
+           layer, (int)msgCode, msg, (unsigned long long)obj,
+           vk_dbg_type(objType), loc);
+
+    // The return value of this function determines whether the call will
+    // be explicitly aborted (to prevent GPU errors) or not. In this case,
+    // we generally want this to be on for the errors.
+    return (flags & VK_DEBUG_REPORT_ERROR_BIT_EXT);
+}
+
+static void vk_cmdpool_uninit(struct mpvk_ctx *vk, struct vk_cmdpool *pool)
+{
+    if (!pool)
+        return;
+
+    // also frees associated command buffers
+    vkDestroyCommandPool(vk->dev, pool->pool, MPVK_ALLOCATOR);
+    for (int n = 0; n < MPVK_MAX_CMDS; n++) {
+        vkDestroyFence(vk->dev, pool->cmds[n].fence, MPVK_ALLOCATOR);
+        vkDestroySemaphore(vk->dev, pool->cmds[n].done, MPVK_ALLOCATOR);
+        talloc_free(pool->cmds[n].callbacks);
+    }
+    talloc_free(pool);
+}
+
+void mpvk_uninit(struct mpvk_ctx *vk)
+{
+    if (!vk->inst)
+        return;
+
+    if (vk->dev) {
+        vk_cmdpool_uninit(vk, vk->pool);
+        vk_malloc_uninit(vk);
+        vkDestroyDevice(vk->dev, MPVK_ALLOCATOR);
+    }
+
+    if (vk->dbg) {
+        // Same deal as creating the debug callback, we need to load this
+        // first.
+        VK_LOAD_PFN(vkDestroyDebugReportCallbackEXT)
+        pfn_vkDestroyDebugReportCallbackEXT(vk->inst, vk->dbg, MPVK_ALLOCATOR);
+    }
+
+    vkDestroySurfaceKHR(vk->inst, vk->surf, MPVK_ALLOCATOR);
+    vkDestroyInstance(vk->inst, MPVK_ALLOCATOR);
+
+    *vk = (struct mpvk_ctx){0};
+}
+
+bool mpvk_instance_init(struct mpvk_ctx *vk, struct mp_log *log, bool debug)
+{
+    *vk = (struct mpvk_ctx) {
+        .log = log,
+    };
+
+    VkInstanceCreateInfo info = {
+        .sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO,
+    };
+
+    if (debug) {
+        // Enables the LunarG standard validation layer, which
+        // is a meta-layer that loads lots of other validators
+        static const char* layers[] = {
+            "VK_LAYER_LUNARG_standard_validation",
+        };
+
+        info.ppEnabledLayerNames = layers;
+        info.enabledLayerCount = MP_ARRAY_SIZE(layers);
+    }
+
+    // Enable whatever extensions were compiled in.
+    static const char *extensions[] = {
+        VK_KHR_SURFACE_EXTENSION_NAME,
+#if HAVE_X11
+        VK_KHR_XLIB_SURFACE_EXTENSION_NAME,
+#endif
+
+        // Extra extensions only used for debugging. These are toggled by
+        // decreasing the enabledExtensionCount, so the number needs to be
+        // synchronized with the code below.
+        VK_EXT_DEBUG_REPORT_EXTENSION_NAME,
+    };
+
+    const int debugExtensionCount = 1;
+
+    info.ppEnabledExtensionNames = extensions;
+    info.enabledExtensionCount = MP_ARRAY_SIZE(extensions);
+
+    if (!debug)
+        info.enabledExtensionCount -= debugExtensionCount;
+
+    MP_VERBOSE(vk, "Creating instance with extensions:\n");
+    for (int i = 0; i < info.enabledExtensionCount; i++)
+        MP_VERBOSE(vk, "    %s\n", info.ppEnabledExtensionNames[i]);
+
+    VkResult res = vkCreateInstance(&info, MPVK_ALLOCATOR, &vk->inst);
+    if (res != VK_SUCCESS) {
+        MP_VERBOSE(vk, "Failed creating instance: %s\n", vk_err(res));
+        return false;
+    }
+
+    if (debug) {
+        // Set up a debug callback to catch validation messages
+        VkDebugReportCallbackCreateInfoEXT dinfo = {
+            .sType = VK_STRUCTURE_TYPE_DEBUG_REPORT_CALLBACK_CREATE_INFO_EXT,
+            .flags = VK_DEBUG_REPORT_INFORMATION_BIT_EXT |
+                     VK_DEBUG_REPORT_WARNING_BIT_EXT |
+                     VK_DEBUG_REPORT_PERFORMANCE_WARNING_BIT_EXT |
+                     VK_DEBUG_REPORT_ERROR_BIT_EXT |
+                     VK_DEBUG_REPORT_DEBUG_BIT_EXT,
+            .pfnCallback = vk_dbg_callback,
+            .pUserData = vk,
+        };
+
+        // Since this is not part of the core spec, we need to load it. This
+        // can't fail because we've already successfully created an instance
+        // with this extension enabled.
+        VK_LOAD_PFN(vkCreateDebugReportCallbackEXT)
+        pfn_vkCreateDebugReportCallbackEXT(vk->inst, &dinfo, MPVK_ALLOCATOR,
+                                           &vk->dbg);
+    }
+
+    return true;
+}
+
+#define MPVK_MAX_DEVICES 16
+
+static bool physd_supports_surface(struct mpvk_ctx *vk, VkPhysicalDevice physd)
+{
+    uint32_t qfnum;
+    vkGetPhysicalDeviceQueueFamilyProperties(physd, &qfnum, NULL);
+
+    for (int i = 0; i < qfnum; i++) {
+        VkBool32 sup;
+        VK(vkGetPhysicalDeviceSurfaceSupportKHR(physd, i, vk->surf, &sup));
+        if (sup)
+            return true;
+    }
+
+error:
+    return false;
+}
+
+bool mpvk_find_phys_device(struct mpvk_ctx *vk, const char *name, bool sw)
+{
+    assert(vk->surf);
+
+    MP_VERBOSE(vk, "Probing for vulkan devices:\n");
+
+    VkPhysicalDevice *devices = NULL;
+    uint32_t num = 0;
+    VK(vkEnumeratePhysicalDevices(vk->inst, &num, NULL));
+    devices = talloc_array(NULL, VkPhysicalDevice, num);
+    VK(vkEnumeratePhysicalDevices(vk->inst, &num, devices));
+
+    // Sorted by "priority". Reuses some m_opt code for convenience
+    static const struct m_opt_choice_alternatives types[] = {
+        {"discrete",   VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU},
+        {"integrated", VK_PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU},
+        {"virtual",    VK_PHYSICAL_DEVICE_TYPE_VIRTUAL_GPU},
+        {"software",   VK_PHYSICAL_DEVICE_TYPE_CPU},
+        {"unknown",    VK_PHYSICAL_DEVICE_TYPE_OTHER},
+        {0}
+    };
+
+    VkPhysicalDeviceProperties props[MPVK_MAX_DEVICES];
+    for (int i = 0; i < num; i++) {
+        vkGetPhysicalDeviceProperties(devices[i], &props[i]);
+        MP_VERBOSE(vk, "    GPU %d: %s (%s)\n", i, props[i].deviceName,
+                   m_opt_choice_str(types, props[i].deviceType));
+    }
+
+    // Iterate through each type in order of decreasing preference
+    for (int t = 0; types[t].name; t++) {
+        // Disallow SW rendering unless explicitly enabled
+        if (types[t].value == VK_PHYSICAL_DEVICE_TYPE_CPU && !sw)
+            continue;
+
+        for (int i = 0; i < num; i++) {
+            VkPhysicalDeviceProperties prop = props[i];
+            if (prop.deviceType != types[t].value)
+                continue;
+            if (name && strcmp(name, prop.deviceName) != 0)
+                continue;
+            if (!physd_supports_surface(vk, devices[i]))
+                continue;
+
+            MP_VERBOSE(vk, "Chose device:\n");
+            MP_VERBOSE(vk, "    Device Name: %s\n", prop.deviceName);
+            MP_VERBOSE(vk, "    Device ID: %x:%x\n",
+                       (unsigned)prop.vendorID, (unsigned)prop.deviceID);
+            MP_VERBOSE(vk, "    Driver version: %d\n", (int)prop.driverVersion);
+            MP_VERBOSE(vk, "    API version: %d.%d.%d\n",
+                    (int)VK_VERSION_MAJOR(prop.apiVersion),
+                    (int)VK_VERSION_MINOR(prop.apiVersion),
+                    (int)VK_VERSION_PATCH(prop.apiVersion));
+            vk->physd = devices[i];
+            vk->limits = prop.limits;
+            talloc_free(devices);
+            return true;
+        }
+    }
+
+error:
+    MP_VERBOSE(vk, "Found no suitable device, giving up.\n");
+    talloc_free(devices);
+    return false;
+}
+
+bool mpvk_pick_surface_format(struct mpvk_ctx *vk)
+{
+    assert(vk->physd);
+
+    VkSurfaceFormatKHR *formats = NULL;
+    int num;
+
+    // Enumerate through the surface formats and find one that we can map to
+    // a ra_format
+    VK(vkGetPhysicalDeviceSurfaceFormatsKHR(vk->physd, vk->surf, &num, NULL));
+    formats = talloc_array(NULL, VkSurfaceFormatKHR, num);
+    VK(vkGetPhysicalDeviceSurfaceFormatsKHR(vk->physd, vk->surf, &num, formats));
+
+    for (int i = 0; i < num; i++) {
+        // A value of VK_FORMAT_UNDEFINED means we can pick anything we want
+        if (formats[i].format == VK_FORMAT_UNDEFINED) {
+            vk->surf_format = (VkSurfaceFormatKHR) {
+                .colorSpace = VK_COLOR_SPACE_SRGB_NONLINEAR_KHR,
+                .format = VK_FORMAT_R16G16B16A16_UNORM,
+            };
+            break;
+        }
+
+        if (formats[i].colorSpace != VK_COLOR_SPACE_SRGB_NONLINEAR_KHR)
+            continue;
+
+        // Format whitelist, since we want only >= 8 bit _UNORM formats
+        switch (formats[i].format) {
+        case VK_FORMAT_R8G8B8_UNORM:
+        case VK_FORMAT_B8G8R8_UNORM:
+        case VK_FORMAT_R8G8B8A8_UNORM:
+        case VK_FORMAT_B8G8R8A8_UNORM:
+        case VK_FORMAT_A8B8G8R8_UNORM_PACK32:
+        case VK_FORMAT_A2R10G10B10_UNORM_PACK32:
+        case VK_FORMAT_A2B10G10R10_UNORM_PACK32:
+        case VK_FORMAT_R16G16B16_UNORM:
+        case VK_FORMAT_R16G16B16A16_UNORM:
+             break; // accept
+        default: continue;
+        }
+
+        vk->surf_format = formats[i];
+        break;
+    }
+
+    talloc_free(formats);
+
+    if (!vk->surf_format.format)
+        goto error;
+
+    return true;
+
+error:
+    MP_ERR(vk, "Failed picking surface format!\n");
+    talloc_free(formats);
+    return false;
+}
+
+static bool vk_cmdpool_init(struct mpvk_ctx *vk, VkDeviceQueueCreateInfo qinfo,
+                            VkQueueFamilyProperties props,
+                            struct vk_cmdpool **out)
+{
+    struct vk_cmdpool *pool = *out = talloc_ptrtype(NULL, pool);
+    *pool = (struct vk_cmdpool) {
+        .qf = qinfo.queueFamilyIndex,
+        .props = props,
+        .qcount = qinfo.queueCount,
+    };
+
+    for (int n = 0; n < pool->qcount; n++)
+        vkGetDeviceQueue(vk->dev, pool->qf, n, &pool->queues[n]);
+
+    VkCommandPoolCreateInfo cinfo = {
+        .sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO,
+        .flags = VK_COMMAND_POOL_CREATE_TRANSIENT_BIT |
+                 VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT,
+        .queueFamilyIndex = pool->qf,
+    };
+
+    VK(vkCreateCommandPool(vk->dev, &cinfo, MPVK_ALLOCATOR, &pool->pool));
+
+    VkCommandBufferAllocateInfo ainfo = {
+        .sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO,
+        .commandPool = pool->pool,
+        .level = VK_COMMAND_BUFFER_LEVEL_PRIMARY,
+        .commandBufferCount = MPVK_MAX_CMDS,
+    };
+
+    VkCommandBuffer cmdbufs[MPVK_MAX_CMDS];
+    VK(vkAllocateCommandBuffers(vk->dev, &ainfo, cmdbufs));
+
+    for (int n = 0; n < MPVK_MAX_CMDS; n++) {
+        struct vk_cmd *cmd = &pool->cmds[n];
+        cmd->pool = pool;
+        cmd->buf = cmdbufs[n];
+
+        VkFenceCreateInfo finfo = {
+            .sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO,
+            .flags = VK_FENCE_CREATE_SIGNALED_BIT,
+        };
+
+        VK(vkCreateFence(vk->dev, &finfo, MPVK_ALLOCATOR, &cmd->fence));
+
+        VkSemaphoreCreateInfo sinfo = {
+            .sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO,
+        };
+
+        VK(vkCreateSemaphore(vk->dev, &sinfo, MPVK_ALLOCATOR, &cmd->done));
+    }
+
+    return true;
+
+error:
+    return false;
+}
+
+bool mpvk_device_init(struct mpvk_ctx *vk, struct mpvk_device_opts opts)
+{
+    assert(vk->physd);
+
+    VkQueueFamilyProperties *qfs = NULL;
+    int qfnum;
+
+    // Enumerate the queue families and find suitable families for each task
+    vkGetPhysicalDeviceQueueFamilyProperties(vk->physd, &qfnum, NULL);
+    qfs = talloc_array(NULL, VkQueueFamilyProperties, qfnum);
+    vkGetPhysicalDeviceQueueFamilyProperties(vk->physd, &qfnum, qfs);
+
+    MP_VERBOSE(vk, "Queue families supported by device:\n");
+
+    for (int i = 0; i < qfnum; i++) {
+        MP_VERBOSE(vk, "QF %d: flags 0x%x num %d\n", i,
+                   (unsigned)qfs[i].queueFlags, (int)qfs[i].queueCount);
+    }
+
+    // For most of our rendering operations, we want to use one "primary" pool,
+    // so just pick the queue family with the most features.
+    int idx = -1;
+    for (int i = 0; i < qfnum; i++) {
+        if (!(qfs[i].queueFlags & VK_QUEUE_GRAPHICS_BIT))
+            continue;
+
+        // QF supports more features
+        if (idx < 0 || qfs[i].queueFlags > qfs[idx].queueFlags)
+            idx = i;
+
+        // QF supports more queues (at the same specialization level)
+        if (qfs[i].queueFlags == qfs[idx].queueFlags &&
+            qfs[i].queueCount > qfs[idx].queueCount)
+        {
+            idx = i;
+        }
+    }
+
+    // Vulkan requires at least one GRAPHICS queue, so if this fails something
+    // is horribly wrong.
+    assert(idx >= 0);
+
+    // Ensure we can actually present to the surface using this queue
+    VkBool32 sup;
+    VK(vkGetPhysicalDeviceSurfaceSupportKHR(vk->physd, idx, vk->surf, &sup));
+    if (!sup) {
+        MP_ERR(vk, "Queue family does not support surface presentation!\n");
+        goto error;
+    }
+
+    // Now that we know which queue families we want, we can create the logical
+    // device
+    assert(opts.queue_count <= MPVK_MAX_QUEUES);
+    static const float priorities[MPVK_MAX_QUEUES] = {0};
+    VkDeviceQueueCreateInfo qinfo = {
+        .sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO,
+        .queueFamilyIndex = idx,
+        .queueCount = MPMIN(qfs[idx].queueCount, opts.queue_count),
+        .pQueuePriorities = priorities,
+    };
+
+    static const char *exts[] = {
+        VK_KHR_SWAPCHAIN_EXTENSION_NAME,
+        VK_NV_GLSL_SHADER_EXTENSION_NAME,
+    };
+
+    VkDeviceCreateInfo dinfo = {
+        .sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO,
+        .queueCreateInfoCount = 1,
+        .pQueueCreateInfos = &qinfo,
+        .ppEnabledExtensionNames = exts,
+        .enabledExtensionCount = MP_ARRAY_SIZE(exts),
+    };
+
+    MP_VERBOSE(vk, "Creating vulkan device...\n");
+    VK(vkCreateDevice(vk->physd, &dinfo, MPVK_ALLOCATOR, &vk->dev));
+
+    vk_malloc_init(vk);
+
+    // Create the vk_cmdpools and all required queues / synchronization objects
+    if (!vk_cmdpool_init(vk, qinfo, qfs[idx], &vk->pool))
+        goto error;
+
+    talloc_free(qfs);
+    return true;
+
+error:
+    MP_ERR(vk, "Failed creating logical device!\n");
+    talloc_free(qfs);
+    return false;
+}
+
+static void run_callbacks(struct mpvk_ctx *vk, struct vk_cmd *cmd)
+{
+    for (int i = 0; i < cmd->num_callbacks; i++) {
+        struct vk_callback *cb = &cmd->callbacks[i];
+        cb->run(cb->priv, cb->arg);
+        *cb = (struct vk_callback){0};
+    }
+
+    cmd->num_callbacks = 0;
+
+    // Also reset vk->last_cmd in case this was the last command to run
+    if (vk->last_cmd == cmd)
+        vk->last_cmd = NULL;
+}
+
+static void wait_for_cmds(struct mpvk_ctx *vk, struct vk_cmd cmds[], int num)
+{
+    if (!num)
+        return;
+
+    VkFence fences[MPVK_MAX_CMDS];
+    for (int i = 0; i < num; i++)
+        fences[i] = cmds[i].fence;
+
+    vkWaitForFences(vk->dev, num, fences, true, UINT64_MAX);
+
+    for (int i = 0; i < num; i++)
+        run_callbacks(vk, &cmds[i]);
+}
+
+void mpvk_pool_wait_idle(struct mpvk_ctx *vk, struct vk_cmdpool *pool)
+{
+    if (!pool)
+        return;
+
+    int idx = pool->cindex, pidx = pool->cindex_pending;
+    if (pidx < idx) { // range doesn't wrap
+        wait_for_cmds(vk, &pool->cmds[pidx], idx - pidx);
+    } else if (pidx > idx) { // range wraps
+        wait_for_cmds(vk, &pool->cmds[pidx], MPVK_MAX_CMDS - pidx);
+        wait_for_cmds(vk, &pool->cmds[0], idx);
+    }
+    pool->cindex_pending = pool->cindex;
+}
+
+void mpvk_dev_wait_idle(struct mpvk_ctx *vk)
+{
+    mpvk_pool_wait_idle(vk, vk->pool);
+}
+
+void mpvk_pool_poll_cmds(struct mpvk_ctx *vk, struct vk_cmdpool *pool,
+                         uint64_t timeout)
+{
+    if (!pool)
+        return;
+
+    // If requested, hard block until at least one command completes
+    if (timeout > 0 && pool->cindex_pending != pool->cindex) {
+        vkWaitForFences(vk->dev, 1, &pool->cmds[pool->cindex_pending].fence,
+                        true, timeout);
+    }
+
+    // Lazily garbage collect the commands based on their status
+    while (pool->cindex_pending != pool->cindex) {
+        struct vk_cmd *cmd = &pool->cmds[pool->cindex_pending];
+        VkResult res = vkGetFenceStatus(vk->dev, cmd->fence);
+        if (res != VK_SUCCESS)
+            break;
+        run_callbacks(vk, cmd);
+        pool->cindex_pending++;
+        pool->cindex_pending %= MPVK_MAX_CMDS;
+    }
+}
+
+void mpvk_dev_poll_cmds(struct mpvk_ctx *vk, uint32_t timeout)
+{
+    mpvk_pool_poll_cmds(vk, vk->pool, timeout);
+}
+
+void vk_dev_callback(struct mpvk_ctx *vk, vk_cb callback, void *p, void *arg)
+{
+    if (vk->last_cmd) {
+        vk_cmd_callback(vk->last_cmd, callback, p, arg);
+    } else {
+        // The device was already idle, so we can just immediately call it
+        callback(p, arg);
+    }
+}
+
+void vk_cmd_callback(struct vk_cmd *cmd, vk_cb callback, void *p, void *arg)
+{
+    MP_TARRAY_GROW(NULL, cmd->callbacks, cmd->num_callbacks);
+    cmd->callbacks[cmd->num_callbacks++] = (struct vk_callback) {
+        .run  = callback,
+        .priv = p,
+        .arg  = arg,
+    };
+}
+
+void vk_cmd_dep(struct vk_cmd *cmd, VkSemaphore dep,
+                VkPipelineStageFlagBits depstage)
+{
+    assert(cmd->num_deps < MPVK_MAX_CMD_DEPS);
+    cmd->deps[cmd->num_deps] = dep;
+    cmd->depstages[cmd->num_deps++] = depstage;
+}
+
+struct vk_cmd *vk_cmd_begin(struct mpvk_ctx *vk, struct vk_cmdpool *pool)
+{
+    // Garbage collect the cmdpool first
+    mpvk_pool_poll_cmds(vk, pool, 0);
+
+    int next = (pool->cindex + 1) % MPVK_MAX_CMDS;
+    if (next == pool->cindex_pending) {
+        MP_ERR(vk, "No free command buffers!\n");
+        goto error;
+    }
+
+    struct vk_cmd *cmd = &pool->cmds[pool->cindex];
+    pool->cindex = next;
+
+    VK(vkResetCommandBuffer(cmd->buf, 0));
+
+    VkCommandBufferBeginInfo binfo = {
+        .sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO,
+        .flags = VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT,
+    };
+
+    VK(vkBeginCommandBuffer(cmd->buf, &binfo));
+
+    return cmd;
+
+error:
+    return NULL;
+}
+
+bool vk_cmd_submit(struct mpvk_ctx *vk, struct vk_cmd *cmd, VkSemaphore *done)
+{
+    VK(vkEndCommandBuffer(cmd->buf));
+
+    struct vk_cmdpool *pool = cmd->pool;
+    VkQueue queue = pool->queues[pool->qindex];
+
+    VkSubmitInfo sinfo = {
+        .sType = VK_STRUCTURE_TYPE_SUBMIT_INFO,
+        .commandBufferCount = 1,
+        .pCommandBuffers = &cmd->buf,
+        .waitSemaphoreCount = cmd->num_deps,
+        .pWaitSemaphores = cmd->deps,
+        .pWaitDstStageMask = cmd->depstages,
+    };
+
+    if (done) {
+        sinfo.signalSemaphoreCount = 1;
+        sinfo.pSignalSemaphores = &cmd->done;
+        *done = cmd->done;
+    }
+
+    VK(vkResetFences(vk->dev, 1, &cmd->fence));
+    VK(vkQueueSubmit(queue, 1, &sinfo, cmd->fence));
+    MP_TRACE(vk, "Submitted command on queue %p (QF %d)\n", (void *)queue,
+             pool->qf);
+
+    for (int i = 0; i < cmd->num_deps; i++)
+        cmd->deps[i] = NULL;
+    cmd->num_deps = 0;
+
+    vk->last_cmd = cmd;
+    return true;
+
+error:
+    return false;
+}
+
+void vk_cmd_cycle_queues(struct mpvk_ctx *vk)
+{
+    struct vk_cmdpool *pool = vk->pool;
+    pool->qindex = (pool->qindex + 1) % pool->qcount;
+}
+
+const VkImageSubresourceRange vk_range = {
+    .aspectMask = VK_IMAGE_ASPECT_COLOR_BIT,
+    .levelCount = 1,
+    .layerCount = 1,
+};
+
+const VkImageSubresourceLayers vk_layers = {
+    .aspectMask = VK_IMAGE_ASPECT_COLOR_BIT,
+    .layerCount = 1,
+};