path: root/system/OpenglSystemCommon/HostConnection.cpp

/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "HostConnection.h"

#include "cutils/properties.h"

#ifdef GOLDFISH_NO_GL
struct gl_client_context_t {
    int placeholder;
};
class GLEncoder : public gl_client_context_t {
public:
    GLEncoder(IOStream*, ChecksumCalculator*) { }
    void setContextAccessor(gl_client_context_t *()) { }
};
struct gl2_client_context_t {
    int placeholder;
};
class GL2Encoder : public gl2_client_context_t {
public:
    GL2Encoder(IOStream*, ChecksumCalculator*) { }
    void setContextAccessor(gl2_client_context_t *()) { }
    void setNoHostError(bool) { }
    void setDrawCallFlushInterval(uint32_t) { }
    void setHasAsyncUnmapBuffer(int) { }
};
#else
#include "GLEncoder.h"
#include "GL2Encoder.h"
#endif

#ifdef GOLDFISH_VULKAN
#include "VkEncoder.h"
#include "AddressSpaceStream.h"
#else
namespace goldfish_vk {
struct VkEncoder {
    VkEncoder(IOStream*) { }
    int placeholder;
};
} // namespace goldfish_vk
class QemuPipeStream;
typedef QemuPipeStream AddressSpaceStream;
AddressSpaceStream* createAddressSpaceStream(size_t bufSize) {
    ALOGE("%s: FATAL: Trying to create ASG stream in unsupported build\n", __func__);
    abort();
}
AddressSpaceStream* createVirtioGpuAddressSpaceStream(size_t bufSize) {
    ALOGE("%s: FATAL: Trying to create virtgpu ASG stream in unsupported build\n", __func__);
    abort();
}
#endif

using goldfish_vk::VkEncoder;

#include "ProcessPipe.h"
#include "QemuPipeStream.h"
#include "TcpStream.h"
#include "ThreadInfo.h"
#include <gralloc_cb_bp.h>
#include <unistd.h>

#ifdef VIRTIO_GPU

#include "VirtioGpuStream.h"
#include "VirtioGpuPipeStream.h"

#include <cros_gralloc_handle.h>
#include <drm/virtgpu_drm.h>
#include <xf86drm.h>

#endif

#undef LOG_TAG
#define LOG_TAG "HostConnection"
#if PLATFORM_SDK_VERSION < 26
#include <cutils/log.h>
#else
#include <log/log.h>
#endif

#define STREAM_BUFFER_SIZE  (4*1024*1024)
#define STREAM_PORT_NUM     22468

static HostConnectionType getConnectionTypeFromProperty() {
#ifdef __Fuchsia__
    return HOST_CONNECTION_ADDRESS_SPACE;
#else
    char transportValue[PROPERTY_VALUE_MAX] = "";
    property_get("ro.kernel.qemu.gltransport", transportValue, "");

    bool isValid = transportValue[0] != '\0';

    if (!isValid) {
        property_get("ro.boot.hardware.gltransport", transportValue, "");
        isValid = transportValue[0] != '\0';
    }

    if (!isValid) return HOST_CONNECTION_QEMU_PIPE;

    if (!strcmp("tcp", transportValue)) return HOST_CONNECTION_TCP;
    if (!strcmp("pipe", transportValue)) return HOST_CONNECTION_QEMU_PIPE;
    if (!strcmp("virtio-gpu", transportValue)) return HOST_CONNECTION_VIRTIO_GPU;
    if (!strcmp("asg", transportValue)) return HOST_CONNECTION_ADDRESS_SPACE;
    if (!strcmp("virtio-gpu-pipe", transportValue)) return HOST_CONNECTION_VIRTIO_GPU_PIPE;
    if (!strcmp("virtio-gpu-asg", transportValue)) return HOST_CONNECTION_VIRTIO_GPU_ADDRESS_SPACE;

    return HOST_CONNECTION_QEMU_PIPE;
#endif
}

static uint32_t getDrawCallFlushIntervalFromProperty() {
    char flushValue[PROPERTY_VALUE_MAX] = "";
    property_get("ro.kernel.qemu.gltransport.drawFlushInterval", flushValue, "");

    bool isValid = flushValue[0] != '\0';
    if (!isValid) return 800;

    long interval = strtol(flushValue, 0, 10);

    if (!interval) return 800;

    return (uint32_t)interval;
}

static GrallocType getGrallocTypeFromProperty() {
    char prop[PROPERTY_VALUE_MAX] = "";
    property_get("ro.hardware.gralloc", prop, "");

    bool isValid = prop[0] != '\0';

    if (!isValid) return GRALLOC_TYPE_RANCHU;

    if (!strcmp("ranchu", prop)) return GRALLOC_TYPE_RANCHU;
    if (!strcmp("minigbm", prop)) return GRALLOC_TYPE_MINIGBM;
    return GRALLOC_TYPE_RANCHU;
}

class GoldfishGralloc : public Gralloc
{
public:
    virtual uint32_t createColorBuffer(
        ExtendedRCEncoderContext* rcEnc,
        int width, int height, uint32_t glformat) {
        return rcEnc->rcCreateColorBuffer(
            rcEnc, width, height, glformat);
    }

    virtual uint32_t getHostHandle(native_handle_t const* handle)
    {
        return cb_handle_t::from(handle)->hostHandle;
    }

    virtual int getFormat(native_handle_t const* handle)
    {
        return cb_handle_t::from(handle)->format;
    }

    virtual size_t getAllocatedSize(native_handle_t const* handle)
    {
        return static_cast<size_t>(cb_handle_t::from(handle)->allocatedSize());
    }
};

static inline uint32_t align_up(uint32_t n, uint32_t a) {
    return ((n + a - 1) / a) * a;
}

#ifdef VIRTIO_GPU

class MinigbmGralloc : public Gralloc {
public:
    virtual uint32_t createColorBuffer(
        ExtendedRCEncoderContext*,
        int width, int height, uint32_t glformat) {

        // Only supported format for pbuffers in gfxstream
        // should be RGBA8
        const uint32_t kGlRGB = 0x1907;
        const uint32_t kGlRGBA = 0x1908;
        const uint32_t kVirglFormatRGBA = 67; // VIRGL_FORMAT_R8G8B8A8_UNORM;
        uint32_t virtgpu_format = 0;
        uint32_t bpp = 0;
        switch (glformat) {
            case kGlRGB:
                ALOGD("Note: egl wanted GL_RGB, still using RGBA");
                virtgpu_format = kVirglFormatRGBA;
                bpp = 4;
                break;
            case kGlRGBA:
                virtgpu_format = kVirglFormatRGBA;
                bpp = 4;
                break;
            default:
                ALOGD("Note: egl wanted 0x%x, still using RGBA", glformat);
                virtgpu_format = kVirglFormatRGBA;
                bpp = 4;
                break;
        }
        const uint32_t kPipeTexture2D = 2; // PIPE_TEXTURE_2D
        const uint32_t kBindRenderTarget = 1 << 1; // VIRGL_BIND_RENDER_TARGET
        struct drm_virtgpu_resource_create res_create;
        memset(&res_create, 0, sizeof(res_create));
        res_create.target = kPipeTexture2D;
        res_create.format = virtgpu_format;
        res_create.bind = kBindRenderTarget;
        res_create.width = width;
        res_create.height = height;
        res_create.depth = 1;
        res_create.array_size = 1;
        res_create.last_level = 0;
        res_create.nr_samples = 0;
        res_create.stride = bpp * width;
        res_create.size = align_up(bpp * width * height, PAGE_SIZE);

        int ret = drmIoctl(m_fd, DRM_IOCTL_VIRTGPU_RESOURCE_CREATE, &res_create);
        if (ret) {
            ALOGE("%s: DRM_IOCTL_VIRTGPU_RESOURCE_CREATE failed with %s (%d)\n", __func__,
                  strerror(errno), errno);
            abort();
        }

        return res_create.res_handle;
    }

    virtual uint32_t getHostHandle(native_handle_t const* handle) {
        struct drm_virtgpu_resource_info info;
        if (!getResInfo(handle, &info)) {
            ALOGE("%s: failed to get resource info\n", __func__);
            return 0;
        }

        return info.res_handle;
    }

    virtual int getFormat(native_handle_t const* handle) {
        return ((cros_gralloc_handle *)handle)->droid_format;
    }

    virtual size_t getAllocatedSize(native_handle_t const* handle) {
        struct drm_virtgpu_resource_info info;
        if (!getResInfo(handle, &info)) {
            ALOGE("%s: failed to get resource info\n", __func__);
            return 0;
        }

        return info.size;
    }

    void setFd(int fd) { m_fd = fd; }

private:

    bool getResInfo(native_handle_t const* handle,
                    struct drm_virtgpu_resource_info* info) {
        memset(info, 0x0, sizeof(*info));
        if (m_fd < 0) {
            ALOGE("%s: Error, rendernode fd missing\n", __func__);
            return false;
        }

        struct drm_gem_close gem_close;
        memset(&gem_close, 0x0, sizeof(gem_close));

        cros_gralloc_handle const* cros_handle =
            reinterpret_cast<cros_gralloc_handle const*>(handle);

        uint32_t prime_handle;
        int ret = drmPrimeFDToHandle(m_fd, cros_handle->fds[0], &prime_handle);
        if (ret) {
            ALOGE("%s: DRM_IOCTL_PRIME_FD_TO_HANDLE failed: %s (errno %d)\n",
                  __func__, strerror(errno), errno);
            return false;
        }

        info->bo_handle = prime_handle;
        gem_close.handle = prime_handle;

        ret = drmIoctl(m_fd, DRM_IOCTL_VIRTGPU_RESOURCE_INFO, info);
        if (ret) {
            ALOGE("%s: DRM_IOCTL_VIRTGPU_RESOURCE_INFO failed: %s (errno %d)\n",
                  __func__, strerror(errno), errno);
            drmIoctl(m_fd, DRM_IOCTL_GEM_CLOSE, &gem_close);
            return false;
        }

        drmIoctl(m_fd, DRM_IOCTL_GEM_CLOSE, &gem_close);
        return true;
    }

    int m_fd = -1;
};

#else

class MinigbmGralloc : public Gralloc {
public:
    virtual uint32_t createColorBuffer(
        ExtendedRCEncoderContext*,
        int width, int height, uint32_t glformat) {
        ALOGE("%s: Error: using minigbm without -DVIRTIO_GPU\n", __func__);
        return 0;
    }

    virtual uint32_t getHostHandle(native_handle_t const* handle) {
        ALOGE("%s: Error: using minigbm without -DVIRTIO_GPU\n", __func__);
        return 0;
    }

    virtual int getFormat(native_handle_t const* handle) {
        ALOGE("%s: Error: using minigbm without -DVIRTIO_GPU\n", __func__);
        return 0;
    }

    virtual size_t getAllocatedSize(native_handle_t const* handle) {
        ALOGE("%s: Error: using minigbm without -DVIRTIO_GPU\n", __func__);
        return 0;
    }

    void setFd(int fd) { m_fd = fd; }

private:

    int m_fd = -1;
};

#endif

class GoldfishProcessPipe : public ProcessPipe
{
public:
    bool processPipeInit(HostConnectionType connType, renderControl_encoder_context_t *rcEnc)
    {
        return ::processPipeInit(connType, rcEnc);
    }
};

static GoldfishGralloc m_goldfishGralloc;
static GoldfishProcessPipe m_goldfishProcessPipe;

HostConnection::HostConnection() :
    m_stream(NULL),
    m_glEnc(NULL),
    m_gl2Enc(NULL),
    m_vkEnc(NULL),
    m_rcEnc(NULL),
    m_checksumHelper(),
    m_glExtensions(),
    m_grallocOnly(true),
    m_noHostError(false),
    m_rendernodeFd(-1),
    m_rendernodeFdOwned(false) { }

HostConnection::~HostConnection()
{
    // round-trip to ensure that queued commands have been processed
    // before process pipe closure is detected.
    if (m_rcEnc) {
        (void) m_rcEnc->rcGetRendererVersion(m_rcEnc);
    }
    if (m_grallocType == GRALLOC_TYPE_MINIGBM) {
        delete m_grallocHelper;
    }
    delete m_stream;
    delete m_glEnc;
    delete m_gl2Enc;
    delete m_rcEnc;

    if (m_rendernodeFdOwned) {
        close(m_rendernodeFd);
    }
}

// static
HostConnection* HostConnection::connect(HostConnection* con) {
    if (!con) return con;

    const enum HostConnectionType connType = getConnectionTypeFromProperty();
    // const enum HostConnectionType connType = HOST_CONNECTION_VIRTIO_GPU;

    switch (connType) {
        case HOST_CONNECTION_ADDRESS_SPACE: {
            AddressSpaceStream *stream = createAddressSpaceStream(STREAM_BUFFER_SIZE);
            if (!stream) {
                ALOGE("Failed to create AddressSpaceStream for host connection!!!\n");
                delete con;
                return NULL;
            }
            con->m_connectionType = HOST_CONNECTION_ADDRESS_SPACE;
            con->m_grallocType = GRALLOC_TYPE_RANCHU;
            con->m_stream = stream;
            con->m_grallocHelper = &m_goldfishGralloc;
            con->m_processPipe = &m_goldfishProcessPipe;
            break;
        }
        case HOST_CONNECTION_QEMU_PIPE: {
            QemuPipeStream *stream = new QemuPipeStream(STREAM_BUFFER_SIZE);
            if (!stream) {
                ALOGE("Failed to create QemuPipeStream for host connection!!!\n");
                delete con;
                return NULL;
            }
            if (stream->connect() < 0) {
                ALOGE("Failed to connect to host (QemuPipeStream)!!!\n");
                delete stream;
                delete con;
                return NULL;
            }
            con->m_connectionType = HOST_CONNECTION_QEMU_PIPE;
            con->m_grallocType = GRALLOC_TYPE_RANCHU;
            con->m_stream = stream;
            con->m_grallocHelper = &m_goldfishGralloc;
            con->m_processPipe = &m_goldfishProcessPipe;
            break;
        }
        case HOST_CONNECTION_TCP: {
#ifdef __Fuchsia__
            ALOGE("Fuchsia doesn't support HOST_CONNECTION_TCP!!!\n");
            delete con;
            return NULL;
            break;
#else
            TcpStream *stream = new TcpStream(STREAM_BUFFER_SIZE);
            if (!stream) {
                ALOGE("Failed to create TcpStream for host connection!!!\n");
                delete con;
                return NULL;
            }

            if (stream->connect("10.0.2.2", STREAM_PORT_NUM) < 0) {
                ALOGE("Failed to connect to host (TcpStream)!!!\n");
                delete stream;
                delete con;
                return NULL;
            }
            con->m_connectionType = HOST_CONNECTION_TCP;
            con->m_grallocType = GRALLOC_TYPE_RANCHU;
            con->m_stream = stream;
            con->m_grallocHelper = &m_goldfishGralloc;
            con->m_processPipe = &m_goldfishProcessPipe;
            break;
#endif
        }
#ifdef VIRTIO_GPU
        case HOST_CONNECTION_VIRTIO_GPU: {
            VirtioGpuStream *stream = new VirtioGpuStream(STREAM_BUFFER_SIZE);
            if (!stream) {
                ALOGE("Failed to create VirtioGpu for host connection!!!\n");
                delete con;
                return NULL;
            }
            if (stream->connect() < 0) {
                ALOGE("Failed to connect to host (VirtioGpu)!!!\n");
                delete stream;
                delete con;
                return NULL;
            }
            con->m_connectionType = HOST_CONNECTION_VIRTIO_GPU;
            con->m_grallocType = GRALLOC_TYPE_MINIGBM;
            con->m_stream = stream;
            con->m_rendernodeFdOwned = false;
            con->m_rendernodeFdOwned = stream->getRendernodeFd();
            MinigbmGralloc* m = new MinigbmGralloc;
            m->setFd(stream->getRendernodeFd());
            con->m_grallocHelper = m;
            con->m_processPipe = stream->getProcessPipe();
            break;
        }
        case HOST_CONNECTION_VIRTIO_GPU_PIPE: {
            VirtioGpuPipeStream *stream = new VirtioGpuPipeStream(STREAM_BUFFER_SIZE);
            if (!stream) {
                ALOGE("Failed to create VirtioGpu for host connection!!!\n");
                delete con;
                return NULL;
            }
            if (stream->connect() < 0) {
                ALOGE("Failed to connect to host (VirtioGpu)!!!\n");
                delete stream;
                delete con;
                return NULL;
            }
            con->m_connectionType = HOST_CONNECTION_VIRTIO_GPU_PIPE;
            con->m_grallocType = getGrallocTypeFromProperty();
            con->m_stream = stream;
            con->m_rendernodeFdOwned = false;
            con->m_rendernodeFd = stream->getRendernodeFd();
            switch (con->m_grallocType) {
                case GRALLOC_TYPE_RANCHU:
                    con->m_grallocHelper = &m_goldfishGralloc;
                    break;
                case GRALLOC_TYPE_MINIGBM: {
                    MinigbmGralloc* m = new MinigbmGralloc;
                    m->setFd(stream->getRendernodeFd());
                    con->m_grallocHelper = m;
                    break;
                }
                default:
                    ALOGE("Fatal: Unknown gralloc type 0x%x\n", con->m_grallocType);
                    abort();
            }
            con->m_processPipe = &m_goldfishProcessPipe;
            break;
        }
#ifndef HOST_BUILD
        case HOST_CONNECTION_VIRTIO_GPU_ADDRESS_SPACE: {
            AddressSpaceStream *stream = createVirtioGpuAddressSpaceStream(STREAM_BUFFER_SIZE);
            if (!stream) {
                ALOGE("Failed to create virtgpu AddressSpaceStream for host connection!!!\n");
                delete con;
                return NULL;
            }
            con->m_connectionType = HOST_CONNECTION_VIRTIO_GPU_ADDRESS_SPACE;
            con->m_grallocType = getGrallocTypeFromProperty();
            con->m_stream = stream;
            con->m_rendernodeFdOwned = false;
            con->m_rendernodeFd = stream->getRendernodeFd();
            switch (con->m_grallocType) {
                case GRALLOC_TYPE_RANCHU:
                    con->m_grallocHelper = &m_goldfishGralloc;
                    break;
                case GRALLOC_TYPE_MINIGBM: {
                    MinigbmGralloc* m = new MinigbmGralloc;
                    m->setFd(stream->getRendernodeFd());
                    con->m_grallocHelper = m;
                    break;
                }
                default:
                    ALOGE("Fatal: Unknown gralloc type 0x%x\n", con->m_grallocType);
                    abort();
            }
            con->m_processPipe = &m_goldfishProcessPipe;
            break;
        }
#endif // !HOST_BUILD
#else
        default:
            break;
#endif
    }

    // send zero 'clientFlags' to the host.
    unsigned int *pClientFlags =
            (unsigned int *)con->m_stream->allocBuffer(sizeof(unsigned int));
    *pClientFlags = 0;
    con->m_stream->commitBuffer(sizeof(unsigned int));

    ALOGD("HostConnection::get() New Host Connection established %p, tid %d\n",
          con, getCurrentThreadId());

    // ALOGD("Address space echo latency check done\n");
    return con;
}

HostConnection *HostConnection::get() {
    return getWithThreadInfo(getEGLThreadInfo());
}

HostConnection *HostConnection::getWithThreadInfo(EGLThreadInfo* tinfo) {
    // Get thread info
    if (!tinfo) {
        return NULL;
    }

    if (tinfo->hostConn == NULL) {
        HostConnection *con = new HostConnection();
        con = connect(con);

        tinfo->hostConn = con;
    }

    return tinfo->hostConn;
}

void HostConnection::exit() {
    EGLThreadInfo *tinfo = getEGLThreadInfo();
    if (!tinfo) {
        return;
    }

    if (tinfo->hostConn) {
        delete tinfo->hostConn;
        tinfo->hostConn = NULL;
    }
}

// static
HostConnection *HostConnection::createUnique() {
    ALOGD("%s: call\n", __func__);
    return connect(new HostConnection());
}

// static
void HostConnection::teardownUnique(HostConnection* con) {
    delete con;
}

GLEncoder *HostConnection::glEncoder()
{
    if (!m_glEnc) {
        m_glEnc = new GLEncoder(m_stream, checksumHelper());
        DBG("HostConnection::glEncoder new encoder %p, tid %d",
            m_glEnc, getCurrentThreadId());
        m_glEnc->setContextAccessor(s_getGLContext);
    }
    return m_glEnc;
}

GL2Encoder *HostConnection::gl2Encoder()
{
    if (!m_gl2Enc) {
        m_gl2Enc = new GL2Encoder(m_stream, checksumHelper());
        DBG("HostConnection::gl2Encoder new encoder %p, tid %d",
            m_gl2Enc, getCurrentThreadId());
        m_gl2Enc->setContextAccessor(s_getGL2Context);
        m_gl2Enc->setNoHostError(m_noHostError);
        m_gl2Enc->setDrawCallFlushInterval(
            getDrawCallFlushIntervalFromProperty());
        m_gl2Enc->setHasAsyncUnmapBuffer(m_rcEnc->hasAsyncUnmapBuffer());
    }
    return m_gl2Enc;
}

VkEncoder *HostConnection::vkEncoder()
{
    if (!m_vkEnc) {
        m_vkEnc = new VkEncoder(m_stream);
    }
    return m_vkEnc;
}

ExtendedRCEncoderContext *HostConnection::rcEncoder()
{
    if (!m_rcEnc) {
        m_rcEnc = new ExtendedRCEncoderContext(m_stream, checksumHelper());
        setChecksumHelper(m_rcEnc);
        queryAndSetSyncImpl(m_rcEnc);
        queryAndSetDmaImpl(m_rcEnc);
        queryAndSetGLESMaxVersion(m_rcEnc);
        queryAndSetNoErrorState(m_rcEnc);
        queryAndSetHostCompositionImpl(m_rcEnc);
        queryAndSetDirectMemSupport(m_rcEnc);
        queryAndSetVulkanSupport(m_rcEnc);
        queryAndSetDeferredVulkanCommandsSupport(m_rcEnc);
        queryAndSetVulkanNullOptionalStringsSupport(m_rcEnc);
        queryAndSetVulkanCreateResourcesWithRequirementsSupport(m_rcEnc);
        queryAndSetVulkanIgnoredHandles(m_rcEnc);
        queryAndSetYUVCache(m_rcEnc);
        queryAndSetAsyncUnmapBuffer(m_rcEnc);
        queryAndSetVirtioGpuNext(m_rcEnc);
        queryHasSharedSlotsHostMemoryAllocator(m_rcEnc);
        queryAndSetVulkanFreeMemorySync(m_rcEnc);
        queryAndSetVirtioGpuNativeSync(m_rcEnc);
        if (m_processPipe) {
            m_processPipe->processPipeInit(m_connectionType, m_rcEnc);
        }
    }
    return m_rcEnc;
}

int HostConnection::getOrCreateRendernodeFd() {
    if (m_rendernodeFd >= 0) return m_rendernodeFd;
#ifdef __Fuchsia__
    return -1;
#else
#ifdef VIRTIO_GPU
    m_rendernodeFd = VirtioGpuPipeStream::openRendernode();
    if (m_rendernodeFd < 0) {
        ALOGE("%s: failed to create secondary "
              "rendernode for host connection. "
              "error: %s (%d)\n", __FUNCTION__,
              strerror(errno), errno);
        return -1;
    }

    // Remember to close it on exit
    m_rendernodeFdOwned = true;
    return m_rendernodeFd;
#else
    return -1;
#endif
#endif
}

gl_client_context_t *HostConnection::s_getGLContext()
{
    EGLThreadInfo *ti = getEGLThreadInfo();
    if (ti->hostConn) {
        return ti->hostConn->m_glEnc;
    }
    return NULL;
}

gl2_client_context_t *HostConnection::s_getGL2Context()
{
    EGLThreadInfo *ti = getEGLThreadInfo();
    if (ti->hostConn) {
        return ti->hostConn->m_gl2Enc;
    }
    return NULL;
}

const std::string& HostConnection::queryGLExtensions(ExtendedRCEncoderContext *rcEnc) {
    if (!m_glExtensions.empty()) {
        return m_glExtensions;
    }

    // Extensions strings are usually quite long, preallocate enough here.
    std::string extensions_buffer(1023, '\0');

    // rcGetGLString() returns required size including the 0-terminator, so
    // account it when passing/using the sizes.
    int extensionSize = rcEnc->rcGetGLString(rcEnc, GL_EXTENSIONS,
                                             &extensions_buffer[0],
                                             extensions_buffer.size() + 1);
    if (extensionSize < 0) {
        extensions_buffer.resize(-extensionSize);
        extensionSize = rcEnc->rcGetGLString(rcEnc, GL_EXTENSIONS,
                                             &extensions_buffer[0],
                                            -extensionSize + 1);
    }

    if (extensionSize > 0) {
        extensions_buffer.resize(extensionSize - 1);
        m_glExtensions.swap(extensions_buffer);
    }

    return m_glExtensions;
}

void HostConnection::queryAndSetHostCompositionImpl(ExtendedRCEncoderContext *rcEnc) {
    const std::string& glExtensions = queryGLExtensions(rcEnc);
    ALOGD("HostComposition ext %s", glExtensions.c_str());
    // make sure V2 is checked first before V1, as host may declare supporting both
    if (glExtensions.find(kHostCompositionV2) != std::string::npos) {
        rcEnc->setHostComposition(HOST_COMPOSITION_V2);
    }
    else if (glExtensions.find(kHostCompositionV1) != std::string::npos) {
        rcEnc->setHostComposition(HOST_COMPOSITION_V1);
    }
    else {
        rcEnc->setHostComposition(HOST_COMPOSITION_NONE);
    }
}

void HostConnection::setChecksumHelper(ExtendedRCEncoderContext *rcEnc) {
    const std::string& glExtensions = queryGLExtensions(rcEnc);
    // check the host supported version
    uint32_t checksumVersion = 0;
    const char* checksumPrefix = ChecksumCalculator::getMaxVersionStrPrefix();
    const char* glProtocolStr = strstr(glExtensions.c_str(), checksumPrefix);
    if (glProtocolStr) {
        uint32_t maxVersion = ChecksumCalculator::getMaxVersion();
        sscanf(glProtocolStr+strlen(checksumPrefix), "%d", &checksumVersion);
        if (maxVersion < checksumVersion) {
            checksumVersion = maxVersion;
        }
        // The ordering of the following two commands matters!
        // Must tell the host first before setting it in the guest
        rcEnc->rcSelectChecksumHelper(rcEnc, checksumVersion, 0);
        m_checksumHelper.setVersion(checksumVersion);
    }
}

void HostConnection::queryAndSetSyncImpl(ExtendedRCEncoderContext *rcEnc) {
    const std::string& glExtensions = queryGLExtensions(rcEnc);
#if PLATFORM_SDK_VERSION <= 16 || (!defined(__i386__) && !defined(__x86_64__))
    rcEnc->setSyncImpl(SYNC_IMPL_NONE);
#else
    if (glExtensions.find(kRCNativeSyncV4) != std::string::npos) {
        rcEnc->setSyncImpl(SYNC_IMPL_NATIVE_SYNC_V4);
    } else if (glExtensions.find(kRCNativeSyncV3) != std::string::npos) {
        rcEnc->setSyncImpl(SYNC_IMPL_NATIVE_SYNC_V3);
    } else if (glExtensions.find(kRCNativeSyncV2) != std::string::npos) {
        rcEnc->setSyncImpl(SYNC_IMPL_NATIVE_SYNC_V2);
    } else {
        rcEnc->setSyncImpl(SYNC_IMPL_NONE);
    }
#endif
}

void HostConnection::queryAndSetDmaImpl(ExtendedRCEncoderContext *rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
#if PLATFORM_SDK_VERSION <= 16 || (!defined(__i386__) && !defined(__x86_64__))
    rcEnc->setDmaImpl(DMA_IMPL_NONE);
#else
    if (glExtensions.find(kDmaExtStr_v1) != std::string::npos) {
        rcEnc->setDmaImpl(DMA_IMPL_v1);
    } else {
        rcEnc->setDmaImpl(DMA_IMPL_NONE);
    }
#endif
}

void HostConnection::queryAndSetGLESMaxVersion(ExtendedRCEncoderContext* rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kGLESMaxVersion_2) != std::string::npos) {
        rcEnc->setGLESMaxVersion(GLES_MAX_VERSION_2);
    } else if (glExtensions.find(kGLESMaxVersion_3_0) != std::string::npos) {
        rcEnc->setGLESMaxVersion(GLES_MAX_VERSION_3_0);
    } else if (glExtensions.find(kGLESMaxVersion_3_1) != std::string::npos) {
        rcEnc->setGLESMaxVersion(GLES_MAX_VERSION_3_1);
    } else if (glExtensions.find(kGLESMaxVersion_3_2) != std::string::npos) {
        rcEnc->setGLESMaxVersion(GLES_MAX_VERSION_3_2);
    } else {
        ALOGW("Unrecognized GLES max version string in extensions: %s",
              glExtensions.c_str());
        rcEnc->setGLESMaxVersion(GLES_MAX_VERSION_2);
    }
}

void HostConnection::queryAndSetNoErrorState(ExtendedRCEncoderContext* rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kGLESNoHostError) != std::string::npos) {
        m_noHostError = true;
    }
}

void HostConnection::queryAndSetDirectMemSupport(ExtendedRCEncoderContext* rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kGLDirectMem) != std::string::npos) {
        rcEnc->featureInfo()->hasDirectMem = true;
    }
}

void HostConnection::queryAndSetVulkanSupport(ExtendedRCEncoderContext* rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kVulkan) != std::string::npos) {
        rcEnc->featureInfo()->hasVulkan = true;
    }
}

void HostConnection::queryAndSetDeferredVulkanCommandsSupport(ExtendedRCEncoderContext* rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kDeferredVulkanCommands) != std::string::npos) {
        rcEnc->featureInfo()->hasDeferredVulkanCommands = true;
    }
}

void HostConnection::queryAndSetVulkanNullOptionalStringsSupport(ExtendedRCEncoderContext* rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kVulkanNullOptionalStrings) != std::string::npos) {
        rcEnc->featureInfo()->hasVulkanNullOptionalStrings = true;
    }
}

void HostConnection::queryAndSetVulkanCreateResourcesWithRequirementsSupport(ExtendedRCEncoderContext* rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kVulkanCreateResourcesWithRequirements) != std::string::npos) {
        rcEnc->featureInfo()->hasVulkanCreateResourcesWithRequirements = true;
    }
}

void HostConnection::queryAndSetVulkanIgnoredHandles(ExtendedRCEncoderContext* rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kVulkanIgnoredHandles) != std::string::npos) {
        rcEnc->featureInfo()->hasVulkanIgnoredHandles = true;
    }
}

void HostConnection::queryAndSetYUVCache(ExtendedRCEncoderContext* rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kYUVCache) != std::string::npos) {
        rcEnc->featureInfo()->hasYUVCache = true;
    }
}

void HostConnection::queryAndSetAsyncUnmapBuffer(ExtendedRCEncoderContext* rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kAsyncUnmapBuffer) != std::string::npos) {
        rcEnc->featureInfo()->hasAsyncUnmapBuffer = true;
    }
}

void HostConnection::queryAndSetVirtioGpuNext(ExtendedRCEncoderContext* rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kVirtioGpuNext) != std::string::npos) {
        rcEnc->featureInfo()->hasVirtioGpuNext = true;
    }
}

void HostConnection::queryHasSharedSlotsHostMemoryAllocator(ExtendedRCEncoderContext *rcEnc) {
    const std::string& glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kHasSharedSlotsHostMemoryAllocator) != std::string::npos) {
        rcEnc->featureInfo()->hasSharedSlotsHostMemoryAllocator = true;
    }
}

void HostConnection::queryAndSetVulkanFreeMemorySync(ExtendedRCEncoderContext *rcEnc) {
    const std::string& glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kVulkanFreeMemorySync) != std::string::npos) {
        rcEnc->featureInfo()->hasVulkanFreeMemorySync = true;
    }
}

void HostConnection::queryAndSetVirtioGpuNativeSync(ExtendedRCEncoderContext* rcEnc) {
    std::string glExtensions = queryGLExtensions(rcEnc);
    if (glExtensions.find(kVirtioGpuNativeSync) != std::string::npos) {
        rcEnc->featureInfo()->hasVirtioGpuNativeSync = true;
    }
}