From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CDB2FCF855A for ; Thu, 3 Oct 2024 07:10:14 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1swFxw-000153-Sh; Thu, 03 Oct 2024 03:09:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1swFxu-00014I-Ni for qemu-devel@nongnu.org; Thu, 03 Oct 2024 03:09:34 -0400 Received: from mail-pj1-x102c.google.com ([2607:f8b0:4864:20::102c]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1swFxp-0006Xl-Cg for qemu-devel@nongnu.org; Thu, 03 Oct 2024 03:09:34 -0400 Received: by mail-pj1-x102c.google.com with SMTP id 98e67ed59e1d1-2e18aa9f06dso472790a91.0 for ; Thu, 03 Oct 2024 00:09:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=daynix-com.20230601.gappssmtp.com; s=20230601; t=1727939368; x=1728544168; darn=nongnu.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=CWOB7nehceDwwKSylWoYlEc1+z/XqFvL41QKwM0ivjQ=; b=mlaWxNTAUsbZBR5cnp5khYSEBs13/SP0z3gRJJYMXZ/pU8Doq0rJ5vkiUfvYnkcZkZ 4tFy47L6JFKE/iwMjJqPyAmtGsZjCol5edjmx1qsr/MvznklrnNz0MzWqekYsxpDCYv+ /xXFRvT80vL+s4ApzEa5pYe/Wi9hd4qhcAexbLpCWEIL2pdivUYbcTT9dwHkUpESi7X0 ocIcEfh9D5ndtR36hn++tkLBR+ZcL3v5jLXWSHmGNxUDHNGPgNrirGmDxp676Hvvuj0f xhfqUHlhwnE5toLs6SuvunfE+awUZsdLw1pcsnlDuoH6eSRoFn2/4s06IEIaODg+RC98 oC1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1727939368; x=1728544168; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=CWOB7nehceDwwKSylWoYlEc1+z/XqFvL41QKwM0ivjQ=; b=qOMeHDHOjuyUjQdSaFc2HzRO6M42mTLroyOlSWSQqZzFUk7NZi08AIyqaT6U1wuYAV lMWtzJZxbpykWdTALfRUAO6mAGJxXP95zfSltDpipfb+SsjVvSLtr3d5RZotRWX5cxWT 6ZbTc1FZaQMr755vLfT+Q7aXUUwGIkzqfeBXq6n9OW8c6ckvEZE+J68gALvEWCdUfTuh LiepC3SaMk/U1N3CrG+OCreSFLyfJPhfWp787tdXvWD6796ahHrwd5oE+HonUqJLd1Wb qzH5TYcWm2DF4WAzwyhzWT/5CBSh/UCWgFwecBsTqcUjS2Xz62PnIluYOOmXVI7CGcnn QhYQ== X-Gm-Message-State: AOJu0YxVWTRaOvsg9YnFlOY83NYR7oUqAoyIyIV5e7kFjkgWawM5munL ldkA9jVYQ4H/T3uwBtBGgoyUKNiLNRGbA5E0/kplav00Nb0bAaEvPBbpWDIhUZU= X-Google-Smtp-Source: AGHT+IGynqgfLUgXIRpfwU25M7JsNY9iqx0CkHnJ9JBYPJcsqYjEnBYNO1PumWcK1F/Gl3yV9szjzA== X-Received: by 2002:a17:90b:3709:b0:2e0:7b03:1908 with SMTP id 98e67ed59e1d1-2e1b38c7582mr3292658a91.10.1727939367733; Thu, 03 Oct 2024 00:09:27 -0700 (PDT) Received: from [157.82.207.107] ([157.82.207.107]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2e18f79717fsm2913504a91.24.2024.10.03.00.09.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 03 Oct 2024 00:09:27 -0700 (PDT) Message-ID: Date: Thu, 3 Oct 2024 16:09:19 +0900 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 01/14] hw/display/apple-gfx: Introduce ParavirtualizedGraphics.Framework support To: Phil Dennis-Jordan Cc: qemu-devel@nongnu.org, agraf@csgraf.de, peter.maydell@linaro.org, pbonzini@redhat.com, rad@semihalf.com, quic_llindhol@quicinc.com, marcin.juszkiewicz@linaro.org, stefanha@redhat.com, mst@redhat.com, slp@redhat.com, richard.henderson@linaro.org, eduardo@habkost.net, marcel.apfelbaum@gmail.com, gaosong@loongson.cn, jiaxun.yang@flygoat.com, chenhuacai@kernel.org, kwolf@redhat.com, hreitz@redhat.com, philmd@linaro.org, shorne@gmail.com, palmer@dabbelt.com, alistair.francis@wdc.com, bmeng.cn@gmail.com, liwei1518@gmail.com, dbarboza@ventanamicro.com, zhiwei_liu@linux.alibaba.com, jcmvbkbc@gmail.com, marcandre.lureau@redhat.com, berrange@redhat.com, qemu-arm@nongnu.org, qemu-block@nongnu.org, qemu-riscv@nongnu.org, Alexander Graf References: <20240928085727.56883-1-phil@philjordan.eu> <20240928085727.56883-2-phil@philjordan.eu> <7f3a1a60-a2f3-433c-8f2e-a2dfe0afdcb5@daynix.com> Content-Language: en-US From: Akihiko Odaki In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: none client-ip=2607:f8b0:4864:20::102c; envelope-from=akihiko.odaki@daynix.com; helo=mail-pj1-x102c.google.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 2024/10/02 22:33, Phil Dennis-Jordan wrote: > Hi, > > Thanks for taking a close look at this. > > There are some further comments, explanations, and also a few questions > inline below. Where I've not commented, I'll just go ahead and make the > suggested change for v4. > > On Tue, 1 Oct 2024 at 11:40, Akihiko Odaki > wrote: > > > > This patch implements a QEMU device that drives PVG for the VMApple > > variant of it. > > I think it is better to name it MMIO variant instead of VMApple. There > is nothing specific to VMApple in: hw/display/apple-gfx-vmapple.m > > > I mean, I don't see it being useful for anything whatsoever outside the > vmapple machine type… But I guess there's little harm in renaming it. I don't know but perhaps we may get vmapple2 or something in the future. > > > > +#include "apple-gfx.h" > > +#include "monitor/monitor.h" > > +#include "hw/sysbus.h" > > +#include "hw/irq.h" > > +#include "trace.h" > > +#import > > + > > +_Static_assert(__aarch64__, ""); > > I don't think this assertion is worthwhile. This assertion will trigger > if you accidentally remove depends on AARCH64 from Kconfig, but I don't > think such code change happens by accident, and there is no reason to > believe that this assertion won't be removed in such a case. > > > As far as I'm aware the Kconfig AARCH64 dependency is for the /target/ > architecture, not the /host/ architecture? The static assert checks for > the latter. The PGIOSurfaceHostDeviceDescriptor type isn't available at > all on non-aarch64 macOS hosts. I've not had any luck with using this > variant of the device on x86-64 hosts simply by disabling any surface > mapper code. > > Incidentally, if you know of a way to depend on a specific /host/ > architecture in the Kconfig, that would be even better. I couldn't spot > a way of doing that though. I got your intention now. The correct way to do that is to check for cpu == 'aarch64'. Having assertion will break qemu-system-aarch64 on Intel Macs. > > > + > > +/* > > + * ParavirtualizedGraphics.Framework only ships header files for > the PCI > > + * variant which does not include IOSFC descriptors and host > devices. We add > > + * their definitions here so that we can also work with the ARM > version. > > + */ > > +typedef bool(^IOSFCRaiseInterrupt)(uint32_t vector); > > +typedef bool(^IOSFCUnmapMemory)( > > +    void *a, void *b, void *c, void *d, void *e, void *f); > > Omit dummy parameter names. > > > > +@end > > + > > +typedef struct AppleGFXVmappleState { > > +    SysBusDevice parent_obj; > > + > > +    AppleGFXState common; > > + > > +    qemu_irq irq_gfx; > > +    qemu_irq irq_iosfc; > > +    MemoryRegion iomem_iosfc; > > +    PGIOSurfaceHostDevice *pgiosfc; > > +} AppleGFXVmappleState; > > + > > +OBJECT_DECLARE_SIMPLE_TYPE(AppleGFXVmappleState, APPLE_GFX_VMAPPLE) > > + > > + > > +static uint64_t apple_iosfc_read(void *opaque, hwaddr offset, > unsigned size) > > +{ > > +    AppleGFXVmappleState *s = opaque; > > +    uint64_t res = 0; > > + > > +    bql_unlock(); > > It is dangerous to unlock BQL at an arbitrary place. Instead of > unlocking, I suggest: > - running [s->pgiosfc mmioReadAtOffset:offset] on another thread > - using a bottom half to request operations that require BQL from the > thread running [s->pgiosfc mmioReadAtOffset:offset] > - calling AIO_WAIT_WHILE() to process the bottom half and to wait for > the completion of [s->pgiosfc mmioReadAtOffset:offset] > > > OK, I think I see what you mean, I'll try to rework things around that > pattern. Any preference on how I kick off the job on the other thread? > As we necessarily need to use libdispatch in a bunch of places in this > code anyway, I guess dispatch_async() would probably be the simplest? Perhaps so. The QEMU way is to use a bottom half with AioContext, but you can't simultaneously run a dispatch queue and AioContext in one thread so you have to use the dispatch queue if you need one. > > > +    res = [s->pgiosfc mmioReadAtOffset:offset]; > > +    bql_lock(); > > + > > +    trace_apple_iosfc_read(offset, res); > > + > > +    return res; > > +} > > + > > +static void apple_iosfc_write( > > +    void *opaque, hwaddr offset, uint64_t val, unsigned size) > > +{ > > +    AppleGFXVmappleState *s = opaque; > > + > > +    trace_apple_iosfc_write(offset, val); > > + > > +    [s->pgiosfc mmioWriteAtOffset:offset value:val]; > > +} > > + > > +static const MemoryRegionOps apple_iosfc_ops = { > > +    .read = apple_iosfc_read, > > +    .write = apple_iosfc_write, > > +    .endianness = DEVICE_LITTLE_ENDIAN, > > +    .valid = { > > +        .min_access_size = 4, > > +        .max_access_size = 8, > > +    }, > > +    .impl = { > > +        .min_access_size = 4, > > +        .max_access_size = 8, > > +    }, > > +}; > > + > > +static PGIOSurfaceHostDevice > *apple_gfx_prepare_iosurface_host_device( > > +    AppleGFXVmappleState *s) > > +{ > > +    PGIOSurfaceHostDeviceDescriptor *iosfc_desc = > > +        [PGIOSurfaceHostDeviceDescriptor new]; > > +    PGIOSurfaceHostDevice *iosfc_host_dev = nil; > > + > > +    iosfc_desc.mapMemory = > > +        ^(uint64_t phys, uint64_t len, bool ro, void **va, void > *e, void *f) { > > +            trace_apple_iosfc_map_memory(phys, len, ro, va, e, f); > > +            MemoryRegion *tmp_mr; > > +            *va = gpa2hva(&tmp_mr, phys, len, NULL); > > Use: dma_memory_map() > > > That doesn't seem to be a precisely equivalent operation. It also says > in its headerdoc, > > Use only for reads OR writes - not for read-modify-write operations. > > which I don't think we can guarantee here at all. > > I guess I can call it twice, once for writing and once for reading, but > given that the dma_memory_unmap operation marks the area dirty, I'm not > it's intended for what I understand the use case here to be: As far as I > can tell, the PV graphics device uses (some) of this memory to exchange > data in a cache-coherent way between host and guest, e.g. as a lock-free > ring buffer, using atomic operations as necessary. (This works because > it's a PV device: it "knows" the other end just another CPU core (or > even the same one) executing in a different hypervisor context.) This > doesn't really match "traditional" DMA patterns where there's either a > read or a write happening. I think the story is a bit different for this VMApple variant. Probably the CPU and GPU in Apple Silicon is cache-coherent so you can map normal memory for GPU without any kind of cache maintenance. Cache conherency of CPU and GPU in Apple Silicon is implied with Apple's documentation; it says you don't need to synchronize resources for MTLStorageModeShared, which is the default for Apple Silicon. https://developer.apple.com/documentation/metal/resource_fundamentals/synchronizing_a_managed_resource_in_macos The name "IOSurface" also implies it is used not only for e.g., ring buffer but also for real data. > > Hunting around some more for alternative APIs, there's also > memory_region_get_ram_ptr(), but I'm not sure its restrictions apply > here either. I think you can call memory_access_is_direct() to check if the requirement is satisfied. It will still break dirty page tracking implemented by dma_memory_unmap() and others, but it's broken for hvf, which does not implement dirty page tracking either. > > > +            return (bool)true; > > Why cast? > > > Good question. Not originally my code, so I've fixed all the instances I > could find now. > > > +        }; > > + > > +    iosfc_desc.unmapMemory = > > +        ^(void *a, void *b, void *c, void *d, void *e, void *f) { > > +            trace_apple_iosfc_unmap_memory(a, b, c, d, e, f); > > +            return (bool)true; > > +        }; > > + > > +    iosfc_desc.raiseInterrupt = ^(uint32_t vector) { > > +        trace_apple_iosfc_raise_irq(vector); > > +        bool locked = bql_locked(); > > +        if (!locked) { > > +            bql_lock(); > > +        } >  > +        qemu_irq_pulse(s->irq_iosfc);> +        if (!locked) { > > +            bql_unlock(); > > +        } > > +        return (bool)true; > > +    }; > > + > > +    iosfc_host_dev = > > +        [[PGIOSurfaceHostDevice alloc] > initWithDescriptor:iosfc_desc]; > > +    [iosfc_desc release]; > > +    return iosfc_host_dev; > > +} > > + > > +static void apple_gfx_vmapple_realize(DeviceState *dev, Error > **errp) > > +{ > > +    @autoreleasepool { > > This autoreleasepool is not used. > > > It is definitely used inside the apple_gfx_common_realize() call. It's > also impossible to say whether [PGDeviceDescriptor new] uses autorelease > semantics internally, so it seemed safer to wrap the whole thing in an > outer pool. Theoretically, It should be safe to assume the callee creates autoreleasepool by themselves as needed in general. We have bunch of code to call Objective-C APIs without creating autoreleasepool in the caller. Practically, [PGDeviceDescriptor new] is likely to be implemented with ARC, which wraps methods in autoreleasepool as necessary. Functions that uses a method that returns autorelease resources should be wrapped with autoreleasepool instead of assuming the caller creates autoreleasepool for them. > > > +        AppleGFXVmappleState *s = APPLE_GFX_VMAPPLE(dev); > > + > > +        PGDeviceDescriptor *desc = [PGDeviceDescriptor new]; > > +        desc.usingIOSurfaceMapper = true; > > +        desc.raiseInterrupt = ^(uint32_t vector) { > > +            bool locked; > > + > > +            trace_apple_gfx_raise_irq(vector); > > +            locked = bql_locked(); > > +            if (!locked) { > > +                bql_lock(); > > +            } > > +            qemu_irq_pulse(s->irq_gfx); > > +            if (!locked) { > > +                bql_unlock(); > > +            } > > +        }; > > + > > +        s->pgiosfc = apple_gfx_prepare_iosurface_host_device(s); > > + > > +        apple_gfx_common_realize(&s->common, desc); > > +        [desc release]; > > +        desc = nil; > > +    } > > +} > > + > > > +++ b/hw/display/apple-gfx.h > > @@ -0,0 +1,57 @@ > > +#ifndef QEMU_APPLE_GFX_H > > +#define QEMU_APPLE_GFX_H > > + > > +#define TYPE_APPLE_GFX_VMAPPLE      "apple-gfx-vmapple" > > +#define TYPE_APPLE_GFX_PCI          "apple-gfx-pci" > > + > > +#include "qemu/typedefs.h" > > + > > +typedef struct AppleGFXState AppleGFXState; > > + > > +void apple_gfx_common_init(Object *obj, AppleGFXState *s, const > char* obj_name); > > + > > +#ifdef __OBJC__ > > This ifdef is unnecessary. > > Ah indeed; at one point, vmapple.c was #including this file, but that's > no longer necessary. > > > > diff --git a/hw/display/apple-gfx.m b/hw/display/apple-gfx.m > > new file mode 100644 > > index 00000000000..837300f9cd4 > > --- /dev/null > > +++ b/hw/display/apple-gfx.m > > @@ -0,0 +1,536 @@ > > +/* > > + * QEMU Apple ParavirtualizedGraphics.framework device > > + * > > + * Copyright © 2023 Amazon.com, Inc. or its affiliates. All > Rights Reserved. > > + * > > + * This work is licensed under the terms of the GNU GPL, version > 2 or later. > > + * See the COPYING file in the top-level directory. > > + * > > + * ParavirtualizedGraphics.framework is a set of libraries that > macOS provides > > + * which implements 3d graphics passthrough to the host as well as a > > + * proprietary guest communication channel to drive it. This > device model > > + * implements support to drive that library from within QEMU. > > + */ > > + > > +#include "apple-gfx.h" > > +#include "trace.h" > > +#include "qemu/main-loop.h" > > +#include "ui/console.h" > > +#include "monitor/monitor.h" > > +#include "qapi/error.h" > > +#include "migration/blocker.h" > > +#include > > +#import > > + > > +static const PGDisplayCoord_t apple_gfx_modes[] = { > > +    { .x = 1440, .y = 1080 }, > > +    { .x = 1280, .y = 1024 }, > > +}; > > + > > +typedef struct PGTask_s { // Name matches forward declaration in > PG header > > Let's name it AppleGFXTask. It is a common practice to have the same > tag > name and typedef in QEMU. > > > This is defining a forward-declared type from framework headers which is > opaque from the framework's point of view. We do not get to choose its > struct name. The alternative is having casts wherever these objects are > being passed between our code and the framework. (See the original v1/v2 > vmapple patch series for how messy this is.) I got the idea. Let's not avoid the typedef then to clarify the naming is not under our control. > > > +static void apple_gfx_render_new_frame(AppleGFXState *s) > > +{ > > +    BOOL r; > > +    void *vram = s->vram; > > +    uint32_t width = surface_width(s->surface); > > +    uint32_t height = surface_height(s->surface); > > +    MTLRegion region = MTLRegionMake2D(0, 0, width, height); > > +    id command_buffer = [s->mtl_queue > commandBuffer]; > > +    id texture = s->texture; > > +    r = [s->pgdisp encodeCurrentFrameToCommandBuffer:command_buffer > > +                                             texture:texture > > +                                              region:region]; > > +    if (!r) { > > +        return; > > +    } > > +    [texture retain]; > > +    if (s->using_managed_texture_storage) { > > +        /* "Managed" textures exist in both VRAM and RAM and > must be synced. */ > > +        id blit = [command_buffer > blitCommandEncoder]; > > +        [blit synchronizeResource:texture]; > > +        [blit endEncoding]; > > +    } > > +    [command_buffer retain]; > > I don't think this call of retain is necessary. The completion handler > gets the command buffer via parameter, which implies the command buffer > is automatically retained until the completion handler finishes. > > > I couldn't find any hard guarantees for this documented anywhere, hence > erring on the side of caution. I think the harm of an additional retain/ > release pair here is quite minor. Apple's sample code doesn't retain for such a case so we can certainly omit it: https://developer.apple.com/documentation/metal/indirect_command_encoding/encoding_indirect_command_buffers_on_the_cpu It's better to avoid additional resource management when the underlying API automatically does things correct. There is a hazard of forgetting release anytime adding one call of retain. > > > > +static void apple_gfx_render_frame_completed(AppleGFXState *s, > void *vram, > > +                                             id texture) > > +{ > > +    --s->pending_frames; > > +    assert(s->pending_frames >= 0); > > + > > +    if (vram != s->vram) { > > +        /* Display mode has changed, drop this old frame. */ > > +        assert(texture != s->texture); > > +        g_free(vram); > > This management of buffers looks a bit convoluted. I suggest > remembering > the width and height instead of pointers and comparing them. This way > you can free resources in set_mode(). > > > Yeah, I suppose that works, I can change that around. > > > +    } else { > > +        copy_mtl_texture_to_surface_mem(texture, vram); > > Writing vram outside BQL may result in tearing. > > > As far as I can tell(*), QXL does the same. I couldn't find any examples > of double-buffering in any of the existing display devices, which would > be the only way to do async updates efficiently and without tearing. In > any case, this solution is still vastly better than a regular VGA > device, which suffers from very visible tearing with macOS on the guest > side anyway. And in an ideal world, we'd pass through the rendered > texture directly to the Cocoa UI code rather than copying out only for > the CPU to draw it back into a window surface which is then passed to > the GPU for host side rendering. But I felt this patch is already very, > very large, and if anyone cares, we can fix imperfections in subsequent > updates. > > (*)The rendering code in that device is also fairly complex, so I may be > misreading it. QXL always modifies the surface with BQL. The surface is modified with qxl_blit(), which is called by qxl_render_update_area_unlocked(). qxl_render_update_area_unlocked() is called by either of qxl_render_update() and qxl_render_update_area_bh(). Both of them are called with BQL. The name includes "unlocked", but it means it is called without holding QXL-internal lock. Most devices works entirely with BQL so they don't perform double buffering. apple-gfx can do the same. > > > +        if (s->gfx_update_requested) { > > +            s->gfx_update_requested = false; > > +            dpy_gfx_update_full(s->con); > > +            graphic_hw_update_done(s->con); >  > +            s->new_frame_ready = false; > > This assignment is unnecessary as s->new_frame_ready is always false > when s->gfx_update_requested. If you want to make sure > s->gfx_update_requested and s->new_frame_ready are mutually exclusive, > use one enum value instead of having two bools. > > > I'll need to refresh my memory and get back to you on this one, it's > been so many months since I actively worked on this code. > > > +        } else { > > +            s->new_frame_ready = true; > > +        } > > +    } > > +    if (s->pending_frames > 0) { > > +        apple_gfx_render_new_frame(s); > > +    } > > +} > > + > > +static void apple_gfx_fb_update_display(void *opaque) > > +{ > > +    AppleGFXState *s = opaque; > > + > > +    dispatch_async(s->render_queue, ^{ > > +        if (s->pending_frames > 0) { > > It should check for s->new_frame_ready as > apple_gfx_render_frame_completed() doesn't check if > s->pending_frames > 0 before calling graphic_hw_update_done(), which is > inconsistent. > > > pending_frames is about guest-side frames that are queued to be rendered > by the host GPU. > new_frame_ready being true indicates that the contents of the Qemu > console surface has been updated with new frame data since the last > gfx_update. > gfx_update_requested indicates that gfx_update is currently awaiting an > async completion (graphic_hw_update_done) but the surface has not > received a new frame content, but the GPU is stily busy drawing one. > > apple_gfx_render_frame_completed is scheduled exactly once per pending > frame, so pending_frames > 0 is an invariant there. (Hence the assert.)> > I don't think there is any inconsistency here, but I'll double check. > It's possible that there's an easier way to express the state machine, > and I'll take a look at that. I meant that apple_gfx_render_frame_completed() does not check if the frame is the last one currently pending. apple_gfx_fb_update_display() ignores a new ready frame when there is a more pending frame, but apple_gfx_render_frame_completed() unconditionally fires graphic_hw_update_done() even if there is a more pending frame. And I think apple_gfx_render_frame_completed() is right and apple_gfx_fb_update_display() is wrong in such a situation. > > Checking if s->pending_frames > 0 both in apple_gfx_fb_update_display() > and apple_gfx_render_frame_completed() is also problematic as that can > defer graphic_hw_update_done() indefinitely if we are getting new > frames > too fast. > > > I see what you mean about this part. I'll have to test it, but I guess > we should reverse the priority, like this: > >         if (s->new_frame_ready) { >             dpy_gfx_update_full(s->con); >             s->new_frame_ready = false; >             graphic_hw_update_done(s->con); >         } else if (s->pending_frames > 0) { >             s->gfx_update_requested = true; >         } else { >             graphic_hw_update_done(s->con); >         } > > 1. If we already have a frame, ready to be displayed, return it immediately. > 2. If the guest has reported that it's completed a frame and the GPU is > currently busy rendering it, defer graphic_hw_update_done until it's done. > 3. If the guest reports no changes to its display, indicate this back to > Qemu as a no-op display update graphic_hw_update_done() with no > dpy_gfx_update* call. Yes, that looks correct. > > > +            s->gfx_update_requested = true; > > +        } else { > > +            if (s->new_frame_ready) { > > +                dpy_gfx_update_full(s->con); > > +                s->new_frame_ready = false; > > +            } > > +            graphic_hw_update_done(s->con); >  > +        }> +    }); > > +} > > + > > +static const GraphicHwOps apple_gfx_fb_ops = { > > +    .gfx_update = apple_gfx_fb_update_display, > > +    .gfx_update_async = true, > > +}; > > + > > +static void update_cursor(AppleGFXState *s) > > +{ > > +    dpy_mouse_set(s->con, s->pgdisp.cursorPosition.x, > > +                  s->pgdisp.cursorPosition.y, s->cursor_show); > > +} > > + > > +static void set_mode(AppleGFXState *s, uint32_t width, uint32_t > height) > > +{ > > +    void *vram = NULL; > > +    DisplaySurface *surface; > > +    MTLTextureDescriptor *textureDescriptor; > > +    id texture = nil; > > +    __block bool no_change = false; > > + > > +    dispatch_sync(s->render_queue, > > Calling dispatch_sync() while holding BQL may result in deadlock. > > Only if any code executed on the same dispatch queue acquires the lock > either directly or transitively. I believe I have ensure this is not > done on the reqnder_queue, have you found anywhere this is the case? The documentation is not clear what threads a dispatch queue runs on. We can have a deadlock if they lock the BQL. > > > +        ^{ > > +            if (s->surface && > > +                width == surface_width(s->surface) && > > +                height == surface_height(s->surface)) { > > +                no_change = true; > > +            } > > +        }); > > + > > +    if (no_change) { > > +        return; > > +    } > > + > > +    vram = g_malloc0(width * height * 4); > > +    surface = qemu_create_displaysurface_from(width, height, > PIXMAN_LE_a8r8g8b8, > > +                                              width * 4, vram); > > + > > +    @autoreleasepool { > > +        textureDescriptor = > > +            [MTLTextureDescriptor > > + > texture2DDescriptorWithPixelFormat:MTLPixelFormatBGRA8Unorm > > +                                             width:width > > +                                            height:height > > +                                         mipmapped:NO]; > > +        textureDescriptor.usage = s->pgdisp.minimumTextureUsage; > > +        texture = [s->mtl > newTextureWithDescriptor:textureDescriptor]; > > +    } > > + > > +    s->using_managed_texture_storage = > > +        (texture.storageMode == MTLStorageModeManaged); > > + > > +    dispatch_sync(s->render_queue, > > +        ^{ > > +            id old_texture = nil; > > +            void *old_vram = s->vram; > > +            s->vram = vram; > > +            s->surface = surface; > > + > > +            dpy_gfx_replace_surface(s->con, surface); > > + > > +            old_texture = s->texture; > > +            s->texture = texture; > > +            [old_texture release]; > > You can just do: > [s->texture release]; > s->texture = texture; > > This will make s->texture dangling between the two statements, but that > don't matter since s->texture is not an atomic variable that can be > safely observed from another thread anyway. > > > + > > +            if (s->pending_frames == 0) { > > +                g_free(old_vram); > > +            } > > +        }); > > +} > > + > > +static void create_fb(AppleGFXState *s) > > +{ > > +    s->con = graphic_console_init(NULL, 0, &apple_gfx_fb_ops, s); > > +    set_mode(s, 1440, 1080); > > + > > +    s->cursor_show = true; > > +} > > + > > +static size_t apple_gfx_get_default_mmio_range_size(void) > > +{ > > +    size_t mmio_range_size; > > +    @autoreleasepool { > > +        PGDeviceDescriptor *desc = [PGDeviceDescriptor new]; > > +        mmio_range_size = desc.mmioLength; > > +        [desc release]; > > +    } > > +    return mmio_range_size; > > +} > > + > > +void apple_gfx_common_init(Object *obj, AppleGFXState *s, const > char* obj_name) > > This function can be merged into apple_gfx_common_realize(). > > > Probably. I'll try it. > > > +{ > > +    Error *local_err = NULL; > > +    int r; > > +    size_t mmio_range_size = > apple_gfx_get_default_mmio_range_size(); > > + > > +    trace_apple_gfx_common_init(obj_name, mmio_range_size); > > +    memory_region_init_io(&s->iomem_gfx, obj, &apple_gfx_ops, s, > obj_name, > > +                          mmio_range_size); > > +    s->iomem_gfx.disable_reentrancy_guard = true; > > Why do you disable reentrancy guard? > > > Perhaps with the proposed AIO_WAIT_WHILE based I/O scheme, this won't be > an issue anymore, but the guard would otherwise keep dropping MMIOs > which immediately caused the PV graphics device to stop making progress. > The MMIO APIs in the PVG framework are thread- and reentrancy-safe, so > we certainly don't need to serialise them on our side. It's better to understand why such reentrancy happens. Reentrancy itself is often a sign of bug. > > > + > > +    /* TODO: PVG framework supports serialising device state: > integrate it! */ > > +    if (apple_gfx_mig_blocker == NULL) { > > +        error_setg(&apple_gfx_mig_blocker, > > +                  "Migration state blocked by apple-gfx display > device"); > > +        r = migrate_add_blocker(&apple_gfx_mig_blocker, &local_err); > > +        if (r < 0) { > > +            error_report_err(local_err); > > Please report the error to the caller of apple_gfx_common_realize() > instead. > > > +        } > > +    } >  > +}> + > > +static void > apple_gfx_register_task_mapping_handlers(AppleGFXState *s, > > + >  PGDeviceDescriptor *desc) > > +{ > > +    desc.createTask = ^(uint64_t vmSize, void * _Nullable * > _Nonnull baseAddress) { > > +        AppleGFXTask *task = apple_gfx_new_task(s, vmSize); > > +        *baseAddress = (void*)task->address; > > nit: please write as (void *) instead of (void*). > > > +        trace_apple_gfx_create_task(vmSize, *baseAddress); > > +        return task; > > +    }; > > + > > > +{ > > +    PGDisplayDescriptor *disp_desc = [PGDisplayDescriptor new]; > > + > > + disp_desc.name = @"QEMU display"; > > +    disp_desc.sizeInMillimeters = NSMakeSize(400., 300.); /* A > 20" display */ > > +    disp_desc.queue = dispatch_get_main_queue(); > > +    disp_desc.newFrameEventHandler = ^(void) { > > +        trace_apple_gfx_new_frame(); > > +        dispatch_async(s->render_queue, ^{ > > +            /* Drop frames if we get too far ahead. */ > > +            if (s->pending_frames >= 2) > > +                return; > > +            ++s->pending_frames; > > +            if (s->pending_frames > 1) { > > +                return; > > +            } > > +            @autoreleasepool { > > +                apple_gfx_render_new_frame(s); > > +            } > > +        }); > > +    }; > > +    disp_desc.modeChangeHandler = ^(PGDisplayCoord_t sizeInPixels, > > +                                    OSType pixelFormat) { > > +        trace_apple_gfx_mode_change(sizeInPixels.x, sizeInPixels.y); > > +        set_mode(s, sizeInPixels.x, sizeInPixels.y); > > +    }; > > +    disp_desc.cursorGlyphHandler = ^(NSBitmapImageRep *glyph, > > +                                     PGDisplayCoord_t hotSpot) { > > +        uint32_t bpp = glyph.bitsPerPixel; > > +        size_t width = glyph.pixelsWide; > > +        size_t height = glyph.pixelsHigh; > > +        size_t padding_bytes_per_row = glyph.bytesPerRow - width > * 4; > > +        const uint8_t* px_data = glyph.bitmapData; > > + > > +        trace_apple_gfx_cursor_set(bpp, width, height); > > + > > +        if (s->cursor) { > > +            cursor_unref(s->cursor); > > +            s->cursor = NULL; > > +        } > > + > > +        if (bpp == 32) { /* Shouldn't be anything else, but just > to be safe...*/ > > +            s->cursor = cursor_alloc(width, height); > > +            s->cursor->hot_x = hotSpot.x; > > +            s->cursor->hot_y = hotSpot.y; > > + > > +            uint32_t *dest_px = s->cursor->data; > > + > > +            for (size_t y = 0; y < height; ++y) { > > +                for (size_t x = 0; x < width; ++x) { > > +                    /* NSBitmapImageRep's red & blue channels > are swapped > > +                     * compared to QEMUCursor's. */ > > +                    *dest_px = > > +                        (px_data[0] << 16u) | > > +                        (px_data[1] <<  8u) | > > +                        (px_data[2] <<  0u) | > > +                        (px_data[3] << 24u); > > +                    ++dest_px; > > +                    px_data += 4; > > +                } > > +                px_data += padding_bytes_per_row; > > +            } > > +            dpy_cursor_define(s->con, s->cursor); > > +            update_cursor(s); > > +        } > > +    }; > > +    disp_desc.cursorShowHandler = ^(BOOL show) { > > +        trace_apple_gfx_cursor_show(show); > > +        s->cursor_show = show; > > +        update_cursor(s); > > +    }; > > +    disp_desc.cursorMoveHandler = ^(void) { > > +        trace_apple_gfx_cursor_move(); > > +        update_cursor(s); > > +    }; > > + > > +    return disp_desc; > > +} > > + > > +static NSArray* > apple_gfx_prepare_display_mode_array(void) > > +{ > > +    PGDisplayMode *modes[ARRAY_SIZE(apple_gfx_modes)]; > > +    NSArray* mode_array = nil; > > +    int i; > > + > > +    for (i = 0; i < ARRAY_SIZE(apple_gfx_modes); i++) { > > +        modes[i] = > > +            [[PGDisplayMode alloc] > initWithSizeInPixels:apple_gfx_modes[i] refreshRateInHz:60.]; > > +    } > > + > > +    mode_array = [NSArray arrayWithObjects:modes > count:ARRAY_SIZE(apple_gfx_modes)]; > > + > > +    for (i = 0; i < ARRAY_SIZE(apple_gfx_modes); i++) { > > +        [modes[i] release]; > > +        modes[i] = nil; > > +    } > > + > > +    return mode_array; > > +} > > + > > +static id copy_suitable_metal_device(void) > > +{ > > +    id dev = nil; > > +    NSArray> *devs = MTLCopyAllDevices(); > > + > > +    /* Prefer a unified memory GPU. Failing that, pick a non- > removable GPU. */ > > +    for (size_t i = 0; i < devs.count; ++i) { > > +        if (devs[i].hasUnifiedMemory) { > > +            dev = devs[i]; > > +            break; > > +        } > > +        if (!devs[i].removable) { > > +            dev = devs[i]; > > +        } > > +    } > > + > > +    if (dev != nil) { > > +        [dev retain]; > > +    } else { > > +        dev = MTLCreateSystemDefaultDevice(); > > +    } > > +    [devs release]; > > + > > +    return dev; > > +} > > + > > +void apple_gfx_common_realize(AppleGFXState *s, > PGDeviceDescriptor *desc) > > +{ > > +    PGDisplayDescriptor *disp_desc = nil; > > + > > +    QTAILQ_INIT(&s->tasks); > > +    s->render_queue = dispatch_queue_create("apple-gfx.render", > > +                                            DISPATCH_QUEUE_SERIAL); > > +    s->mtl = copy_suitable_metal_device(); > > +    s->mtl_queue = [s->mtl newCommandQueue]; > > + > > +    desc.device = s->mtl; > > + > > +    apple_gfx_register_task_mapping_handlers(s, desc); > > + > > +    s->pgdev = PGNewDeviceWithDescriptor(desc); > > + > > +    disp_desc = apple_gfx_prepare_display_handlers(s); > > +    s->pgdisp = [s->pgdev newDisplayWithDescriptor:disp_desc > > +                                              port:0 > serialNum:1234]; > > +    [disp_desc release]; > > +    s->pgdisp.modeList = apple_gfx_prepare_display_mode_array(); > > + > > +    create_fb(s); > > +} > > diff --git a/hw/display/meson.build b/hw/display/meson.build > > index 7db05eace97..70d855749c0 100644 > > --- a/hw/display/meson.build > > +++ b/hw/display/meson.build > > @@ -65,6 +65,8 @@ system_ss.add(when: 'CONFIG_ARTIST', if_true: > files('artist.c')) > > > >   system_ss.add(when: 'CONFIG_ATI_VGA', if_true: [files('ati.c', > 'ati_2d.c', 'ati_dbg.c'), pixman]) > > > > +system_ss.add(when: 'CONFIG_MAC_PVG',         if_true: > [files('apple-gfx.m'), pvg, metal]) > > +system_ss.add(when: 'CONFIG_MAC_PVG_VMAPPLE', if_true: > [files('apple-gfx-vmapple.m'), pvg, metal]) > > > >   if config_all_devices.has_key('CONFIG_VIRTIO_GPU') > >     virtio_gpu_ss = ss.source_set() > > diff --git a/hw/display/trace-events b/hw/display/trace-events > > index 781f8a33203..1809a358e36 100644 > > --- a/hw/display/trace-events > > +++ b/hw/display/trace-events > > @@ -191,3 +191,29 @@ dm163_bits_ppi(unsigned dest_width) > "dest_width : %u" > >   dm163_leds(int led, uint32_t value) "led %d: 0x%x" > >   dm163_channels(int channel, uint8_t value) "channel %d: 0x%x" > >   dm163_refresh_rate(uint32_t rr) "refresh rate %d" > > + > > +# apple-gfx.m > > +apple_gfx_read(uint64_t offset, uint64_t res) > "offset=0x%"PRIx64" res=0x%"PRIx64 > > +apple_gfx_write(uint64_t offset, uint64_t val) > "offset=0x%"PRIx64" val=0x%"PRIx64 > > +apple_gfx_create_task(uint32_t vm_size, void *va) "vm_size=0x%x > base_addr=%p" > > +apple_gfx_destroy_task(void *task) "task=%p" > > +apple_gfx_map_memory(void *task, uint32_t range_count, uint64_t > virtual_offset, uint32_t read_only) "task=%p range_count=0x%x > virtual_offset=0x%"PRIx64" read_only=%d" > > +apple_gfx_map_memory_range(uint32_t i, uint64_t phys_addr, > uint64_t phys_len) "[%d] phys_addr=0x%"PRIx64" phys_len=0x%"PRIx64 > > +apple_gfx_remap(uint64_t retval, uint64_t source, uint64_t > target) "retval=%"PRId64" source=0x%"PRIx64" target=0x%"PRIx64 > > +apple_gfx_unmap_memory(void *task, uint64_t virtual_offset, > uint64_t length) "task=%p virtual_offset=0x%"PRIx64" length=0x%"PRIx64 > > +apple_gfx_read_memory(uint64_t phys_address, uint64_t length, > void *dst) "phys_addr=0x%"PRIx64" length=0x%"PRIx64" dest=%p" > > +apple_gfx_raise_irq(uint32_t vector) "vector=0x%x" > > +apple_gfx_new_frame(void) "" > > +apple_gfx_mode_change(uint64_t x, uint64_t y) "x=%"PRId64" > y=%"PRId64 > > +apple_gfx_cursor_set(uint32_t bpp, uint64_t width, uint64_t > height) "bpp=%d width=%"PRId64" height=0x%"PRId64 > > +apple_gfx_cursor_show(uint32_t show) "show=%d" > > +apple_gfx_cursor_move(void) "" > > +apple_gfx_common_init(const char *device_name, size_t mmio_size) > "device: %s; MMIO size: %zu bytes" > > + > > +# apple-gfx-vmapple.m > > +apple_iosfc_read(uint64_t offset, uint64_t res) > "offset=0x%"PRIx64" res=0x%"PRIx64 > > +apple_iosfc_write(uint64_t offset, uint64_t val) > "offset=0x%"PRIx64" val=0x%"PRIx64 > > +apple_iosfc_map_memory(uint64_t phys, uint64_t len, uint32_t ro, > void *va, void *e, void *f) "phys=0x%"PRIx64" len=0x%"PRIx64" ro=%d > va=%p e=%p f=%p" > > +apple_iosfc_unmap_memory(void *a, void *b, void *c, void *d, > void *e, void *f) "a=%p b=%p c=%p d=%p e=%p f=%p" > > +apple_iosfc_raise_irq(uint32_t vector) "vector=0x%x" > > + > > diff --git a/meson.build b/meson.build > > index 10464466ff3..f09df3f09d5 100644 > > --- a/meson.build > > +++ b/meson.build > > @@ -741,6 +741,8 @@ socket = [] > >   version_res = [] > >   coref = [] > >   iokit = [] > > +pvg = [] > > +metal = [] > >   emulator_link_args = [] > >   midl = not_found > >   widl = not_found > > @@ -762,6 +764,8 @@ elif host_os == 'darwin' > >     coref = dependency('appleframeworks', modules: 'CoreFoundation') > >     iokit = dependency('appleframeworks', modules: 'IOKit', > required: false) > >     host_dsosuf = '.dylib' > > +  pvg = dependency('appleframeworks', modules: > 'ParavirtualizedGraphics') > > +  metal = dependency('appleframeworks', modules: 'Metal') > >   elif host_os == 'sunos' > >     socket = [cc.find_library('socket'), > >               cc.find_library('nsl'), >