[PATCH 44/55] drivers: hv: dxgkrnl: Implement known escapes
From: Eric Curtin
Date: Thu Mar 19 2026 - 16:34:40 EST
From: Iouri Tarassov <iourit@xxxxxxxxxxxxxxxxxxx>
Implement an escape to build test command buffer.
Implement other known escapes.
Signed-off-by: Iouri Tarassov <iourit@xxxxxxxxxxxxxxxxxxx>
[kms: forward port to 6.6 from 6.1. No code changes made.]
Signed-off-by: Kelsey Steele <kelseysteele@xxxxxxxxxxxxx>
---
drivers/hv/dxgkrnl/dxgkrnl.h | 3 +-
drivers/hv/dxgkrnl/dxgvmbus.c | 40 +++++---
drivers/hv/dxgkrnl/ioctl.c | 170 +++++++++++++++++++++++++++++-----
include/uapi/misc/d3dkmthk.h | 31 +++++++
4 files changed, 205 insertions(+), 39 deletions(-)
diff --git a/drivers/hv/dxgkrnl/dxgkrnl.h b/drivers/hv/dxgkrnl/dxgkrnl.h
index ebf81cffa289..9599ec8e0f1d 100644
--- a/drivers/hv/dxgkrnl/dxgkrnl.h
+++ b/drivers/hv/dxgkrnl/dxgkrnl.h
@@ -953,7 +953,8 @@ int dxgvmb_send_query_alloc_residency(struct dxgprocess *process,
*args);
int dxgvmb_send_escape(struct dxgprocess *process,
struct dxgadapter *adapter,
- struct d3dkmt_escape *args);
+ struct d3dkmt_escape *args,
+ bool user_mode);
int dxgvmb_send_query_vidmem_info(struct dxgprocess *process,
struct dxgadapter *adapter,
struct d3dkmt_queryvideomemoryinfo *args,
diff --git a/drivers/hv/dxgkrnl/dxgvmbus.c b/drivers/hv/dxgkrnl/dxgvmbus.c
index 2436e1a7bc73..de28c6162a70 100644
--- a/drivers/hv/dxgkrnl/dxgvmbus.c
+++ b/drivers/hv/dxgkrnl/dxgvmbus.c
@@ -2174,7 +2174,8 @@ int dxgvmb_send_query_alloc_residency(struct dxgprocess *process,
int dxgvmb_send_escape(struct dxgprocess *process,
struct dxgadapter *adapter,
- struct d3dkmt_escape *args)
+ struct d3dkmt_escape *args,
+ bool user_mode)
{
int ret;
struct dxgkvmb_command_escape *command = NULL;
@@ -2203,13 +2204,18 @@ int dxgvmb_send_escape(struct dxgprocess *process,
command->priv_drv_data_size = args->priv_drv_data_size;
command->context = args->context;
if (args->priv_drv_data_size) {
- ret = copy_from_user(command->priv_drv_data,
- args->priv_drv_data,
- args->priv_drv_data_size);
- if (ret) {
- DXG_ERR("failed to copy priv data");
- ret = -EFAULT;
- goto cleanup;
+ if (user_mode) {
+ ret = copy_from_user(command->priv_drv_data,
+ args->priv_drv_data,
+ args->priv_drv_data_size);
+ if (ret) {
+ DXG_ERR("failed to copy priv data");
+ ret = -EFAULT;
+ goto cleanup;
+ }
+ } else {
+ memcpy(command->priv_drv_data, args->priv_drv_data,
+ args->priv_drv_data_size);
}
}
@@ -2220,12 +2226,18 @@ int dxgvmb_send_escape(struct dxgprocess *process,
goto cleanup;
if (args->priv_drv_data_size) {
- ret = copy_to_user(args->priv_drv_data,
- command->priv_drv_data,
- args->priv_drv_data_size);
- if (ret) {
- DXG_ERR("failed to copy priv data");
- ret = -EINVAL;
+ if (user_mode) {
+ ret = copy_to_user(args->priv_drv_data,
+ command->priv_drv_data,
+ args->priv_drv_data_size);
+ if (ret) {
+ DXG_ERR("failed to copy priv data");
+ ret = -EINVAL;
+ }
+ } else {
+ memcpy(args->priv_drv_data,
+ command->priv_drv_data,
+ args->priv_drv_data_size);
}
}
diff --git a/drivers/hv/dxgkrnl/ioctl.c b/drivers/hv/dxgkrnl/ioctl.c
index 5ff4b27af19d..f8ca79d098f3 100644
--- a/drivers/hv/dxgkrnl/ioctl.c
+++ b/drivers/hv/dxgkrnl/ioctl.c
@@ -4257,10 +4257,8 @@ dxgkio_change_vidmem_reservation(struct dxgprocess *process, void *__user inargs
}
ret = dxgadapter_acquire_lock_shared(adapter);
- if (ret < 0) {
- adapter = NULL;
+ if (ret < 0)
goto cleanup;
- }
adapter_locked = true;
args.adapter.v = 0;
ret = dxgvmb_send_change_vidmem_reservation(process, adapter,
@@ -4299,10 +4297,8 @@ dxgkio_query_clock_calibration(struct dxgprocess *process, void *__user inargs)
}
ret = dxgadapter_acquire_lock_shared(adapter);
- if (ret < 0) {
- adapter = NULL;
+ if (ret < 0)
goto cleanup;
- }
adapter_locked = true;
args.adapter = adapter->host_handle;
@@ -4349,10 +4345,8 @@ dxgkio_flush_heap_transitions(struct dxgprocess *process, void *__user inargs)
}
ret = dxgadapter_acquire_lock_shared(adapter);
- if (ret < 0) {
- adapter = NULL;
+ if (ret < 0)
goto cleanup;
- }
adapter_locked = true;
args.adapter = adapter->host_handle;
@@ -4417,6 +4411,134 @@ dxgkio_invalidate_cache(struct dxgprocess *process, void *__user inargs)
return ret;
}
+static int
+build_test_command_buffer(struct dxgprocess *process,
+ struct dxgadapter *adapter,
+ struct d3dkmt_escape *args)
+{
+ int ret;
+ struct d3dddi_buildtestcommandbuffer cmd;
+ struct d3dkmt_escape newargs = *args;
+ u32 buf_size;
+ struct d3dddi_buildtestcommandbuffer *buf = NULL;
+ struct d3dddi_buildtestcommandbuffer *__user ucmd;
+
+ ucmd = args->priv_drv_data;
+ if (args->priv_drv_data_size <
+ sizeof(struct d3dddi_buildtestcommandbuffer)) {
+ DXG_ERR("Invalid private data size");
+ return -EINVAL;
+ }
+ ret = copy_from_user(&cmd, ucmd, sizeof(cmd));
+ if (ret) {
+ DXG_ERR("Failed to copy private data");
+ return -EFAULT;
+ }
+
+ if (cmd.dma_buffer_size < sizeof(u32) ||
+ cmd.dma_buffer_size > D3DDDI_MAXTESTBUFFERSIZE ||
+ cmd.dma_buffer_priv_data_size >
+ D3DDDI_MAXTESTBUFFERPRIVATEDRIVERDATASIZE) {
+ DXG_ERR("Invalid DMA buffer or private data size");
+ return -EINVAL;
+ }
+ /* Allocate a new buffer for the escape call */
+ buf_size = sizeof(struct d3dddi_buildtestcommandbuffer) +
+ cmd.dma_buffer_size +
+ cmd.dma_buffer_priv_data_size;
+ buf = vzalloc(buf_size);
+ if (buf == NULL) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+ *buf = cmd;
+ buf->dma_buffer = NULL;
+ buf->dma_buffer_priv_data = NULL;
+
+ /* Replace private data in the escape arguments and call the host */
+ newargs.priv_drv_data = buf;
+ newargs.priv_drv_data_size = buf_size;
+ ret = dxgvmb_send_escape(process, adapter, &newargs, false);
+ if (ret) {
+ DXG_ERR("Host failed escape");
+ goto cleanup;
+ }
+
+ ret = copy_to_user(&ucmd->dma_buffer_size, &buf->dma_buffer_size,
+ sizeof(u32));
+ if (ret) {
+ DXG_ERR("Failed to dma size to user");
+ ret = -EFAULT;
+ goto cleanup;
+ }
+ ret = copy_to_user(&ucmd->dma_buffer_priv_data_size,
+ &buf->dma_buffer_priv_data_size,
+ sizeof(u32));
+ if (ret) {
+ DXG_ERR("Failed to dma private data size to user");
+ ret = -EFAULT;
+ goto cleanup;
+ }
+ ret = copy_to_user(cmd.dma_buffer, (char *)buf + sizeof(*buf),
+ buf->dma_buffer_size);
+ if (ret) {
+ DXG_ERR("Failed to copy dma buffer to user");
+ ret = -EFAULT;
+ goto cleanup;
+ }
+ if (buf->dma_buffer_priv_data_size) {
+ ret = copy_to_user(cmd.dma_buffer_priv_data,
+ (char *)buf + sizeof(*buf) + cmd.dma_buffer_size,
+ buf->dma_buffer_priv_data_size);
+ if (ret) {
+ DXG_ERR("Failed to copy private data to user");
+ ret = -EFAULT;
+ goto cleanup;
+ }
+ }
+
+cleanup:
+ if (buf)
+ vfree(buf);
+ return ret;
+}
+
+static int
+driver_known_escape(struct dxgprocess *process,
+ struct dxgadapter *adapter,
+ struct d3dkmt_escape *args)
+{
+ enum d3dkmt_escapetype escape_type;
+ int ret = 0;
+
+ if (args->priv_drv_data_size < sizeof(enum d3dddi_knownescapetype))
+ {
+ DXG_ERR("Invalid private data size");
+ return -EINVAL;
+ }
+ ret = copy_from_user(&escape_type, args->priv_drv_data,
+ sizeof(escape_type));
+ if (ret) {
+ DXG_ERR("Failed to read escape type");
+ return -EFAULT;
+ }
+ switch (escape_type) {
+ case _D3DDDI_DRIVERESCAPETYPE_TRANSLATEALLOCATIONHANDLE:
+ case _D3DDDI_DRIVERESCAPETYPE_TRANSLATERESOURCEHANDLE:
+ /*
+ * The host and VM handles are the same
+ */
+ break;
+ case _D3DDDI_DRIVERESCAPETYPE_BUILDTESTCOMMANDBUFFER:
+ ret = build_test_command_buffer(process, adapter, args);
+ break;
+ default:
+ ret = dxgvmb_send_escape(process, adapter, args, true);
+ break;
+ }
+ return ret;
+}
+
static int
dxgkio_escape(struct dxgprocess *process, void *__user inargs)
{
@@ -4438,14 +4560,17 @@ dxgkio_escape(struct dxgprocess *process, void *__user inargs)
}
ret = dxgadapter_acquire_lock_shared(adapter);
- if (ret < 0) {
- adapter = NULL;
+ if (ret < 0)
goto cleanup;
- }
adapter_locked = true;
args.adapter = adapter->host_handle;
- ret = dxgvmb_send_escape(process, adapter, &args);
+
+ if (args.type == _D3DKMT_ESCAPE_DRIVERPRIVATE &&
+ args.flags.driver_known_escape)
+ ret = driver_known_escape(process, adapter, &args);
+ else
+ ret = dxgvmb_send_escape(process, adapter, &args, true);
cleanup:
@@ -4485,10 +4610,8 @@ dxgkio_query_vidmem_info(struct dxgprocess *process, void *__user inargs)
}
ret = dxgadapter_acquire_lock_shared(adapter);
- if (ret < 0) {
- adapter = NULL;
+ if (ret < 0)
goto cleanup;
- }
adapter_locked = true;
args.adapter = adapter->host_handle;
@@ -5323,9 +5446,9 @@ dxgkio_is_feature_enabled(struct dxgprocess *process, void *__user inargs)
{
struct d3dkmt_isfeatureenabled args;
struct dxgadapter *adapter = NULL;
- struct dxgglobal *dxgglobal = dxggbl();
struct d3dkmt_isfeatureenabled *__user uargs = inargs;
int ret;
+ bool adapter_locked = false;
ret = copy_from_user(&args, inargs, sizeof(args));
if (ret) {
@@ -5340,11 +5463,10 @@ dxgkio_is_feature_enabled(struct dxgprocess *process, void *__user inargs)
goto cleanup;
}
- if (adapter) {
- ret = dxgadapter_acquire_lock_shared(adapter);
- if (ret < 0)
- goto cleanup;
- }
+ ret = dxgadapter_acquire_lock_shared(adapter);
+ if (ret < 0)
+ goto cleanup;
+ adapter_locked = true;
ret = dxgvmb_send_is_feature_enabled(adapter, &args);
if (ret)
@@ -5354,10 +5476,10 @@ dxgkio_is_feature_enabled(struct dxgprocess *process, void *__user inargs)
cleanup:
- if (adapter) {
+ if (adapter_locked)
dxgadapter_release_lock_shared(adapter);
+ if (adapter)
kref_put(&adapter->adapter_kref, dxgadapter_release);
- }
DXG_TRACE_IOCTL_END(ret);
return ret;
diff --git a/include/uapi/misc/d3dkmthk.h b/include/uapi/misc/d3dkmthk.h
index 5b345ddaf66e..db40e8ff40b0 100644
--- a/include/uapi/misc/d3dkmthk.h
+++ b/include/uapi/misc/d3dkmthk.h
@@ -237,6 +237,37 @@ struct d3dddi_destroypagingqueue {
struct d3dkmthandle paging_queue;
};
+enum d3dddi_knownescapetype {
+ _D3DDDI_DRIVERESCAPETYPE_TRANSLATEALLOCATIONHANDLE = 0,
+ _D3DDDI_DRIVERESCAPETYPE_TRANSLATERESOURCEHANDLE = 1,
+ _D3DDDI_DRIVERESCAPETYPE_CPUEVENTUSAGE = 2,
+ _D3DDDI_DRIVERESCAPETYPE_BUILDTESTCOMMANDBUFFER = 3,
+};
+
+struct d3dddi_translate_allocation_handle {
+ enum d3dddi_knownescapetype escape_type;
+ struct d3dkmthandle allocation;
+};
+
+struct d3dddi_testcommand {
+ char buffer[72];
+};
+
+#define D3DDDI_MAXTESTBUFFERSIZE 4096
+#define D3DDDI_MAXTESTBUFFERPRIVATEDRIVERDATASIZE 1024
+
+struct d3dddi_buildtestcommandbuffer {
+ enum d3dddi_knownescapetype escape_type;
+ struct d3dkmthandle device;
+ struct d3dkmthandle context;
+ __u32 flags;
+ struct d3dddi_testcommand command;
+ void *dma_buffer;
+ void *dma_buffer_priv_data;
+ __u32 dma_buffer_size;
+ __u32 dma_buffer_priv_data_size;
+};
+
enum d3dkmt_escapetype {
_D3DKMT_ESCAPE_DRIVERPRIVATE = 0,
_D3DKMT_ESCAPE_VIDMM = 1,