From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Iouri Tarassov Date: Fri, 8 Oct 2021 14:17:39 -0700 Subject: drivers: hv: dxgkrnl: Add support to map guest pages by host Implement support for mapping guest memory pages by the host. This removes hyper-v limitations of using GPADL (guest physical address list). Dxgkrnl uses hyper-v GPADLs to share guest system memory with the host. This method has limitations: - a single GPADL can represent only ~32MB of memory - there is a limit of how much memory the total size of GPADLs in a VM can represent. To avoid these limitations the host implemented mapping guest memory pages. Presence of this support is determined by reading PCI config space. When the support is enabled, dxgkrnl does not use GPADLs and instead uses the following code flow: - memory pages of an existing system memory buffer are pinned - PFNs of the pages are sent to the host via a VM bus message - the host maps the PFNs to get access to the memory Signed-off-by: Iouri Tarassov [kms: Forward port to v6.1] Signed-off-by: Kelsey Steele --- drivers/hv/dxgkrnl/Makefile | 2 +- drivers/hv/dxgkrnl/dxgkrnl.h | 1 + drivers/hv/dxgkrnl/dxgmodule.c | 33 ++- drivers/hv/dxgkrnl/dxgvmbus.c | 117 +++++++--- drivers/hv/dxgkrnl/dxgvmbus.h | 10 + drivers/hv/dxgkrnl/misc.c | 1 + 6 files changed, 129 insertions(+), 35 deletions(-) diff --git a/drivers/hv/dxgkrnl/Makefile b/drivers/hv/dxgkrnl/Makefile index 111111111111..222222222222 100644 --- a/drivers/hv/dxgkrnl/Makefile +++ b/drivers/hv/dxgkrnl/Makefile @@ -2,4 +2,4 @@ # Makefile for the hyper-v compute device driver (dxgkrnl). obj-$(CONFIG_DXGKRNL) += dxgkrnl.o -dxgkrnl-y := dxgmodule.o hmgr.o misc.o dxgadapter.o ioctl.o dxgvmbus.o dxgprocess.o +dxgkrnl-y := dxgmodule.o hmgr.o misc.o dxgadapter.o ioctl.o dxgvmbus.o dxgprocess.o diff --git a/drivers/hv/dxgkrnl/dxgkrnl.h b/drivers/hv/dxgkrnl/dxgkrnl.h index 111111111111..222222222222 100644 --- a/drivers/hv/dxgkrnl/dxgkrnl.h +++ b/drivers/hv/dxgkrnl/dxgkrnl.h @@ -316,6 +316,7 @@ struct dxgglobal { bool misc_registered; bool pci_registered; bool vmbus_registered; + bool map_guest_pages_enabled; }; static inline struct dxgglobal *dxggbl(void) diff --git a/drivers/hv/dxgkrnl/dxgmodule.c b/drivers/hv/dxgkrnl/dxgmodule.c index 111111111111..222222222222 100644 --- a/drivers/hv/dxgkrnl/dxgmodule.c +++ b/drivers/hv/dxgkrnl/dxgmodule.c @@ -147,7 +147,7 @@ void dxgglobal_remove_host_event(struct dxghostevent *event) void signal_host_cpu_event(struct dxghostevent *eventhdr) { - struct dxghosteventcpu *event = (struct dxghosteventcpu *)eventhdr; + struct dxghosteventcpu *event = (struct dxghosteventcpu *)eventhdr; if (event->remove_from_list || event->destroy_after_signal) { @@ -426,7 +426,11 @@ const struct file_operations dxgk_fops = { #define DXGK_VMBUS_VGPU_LUID_OFFSET (DXGK_VMBUS_VERSION_OFFSET + \ sizeof(u32)) -/* The guest writes its capabilities to this address */ +/* The host caps (dxgk_vmbus_hostcaps) */ +#define DXGK_VMBUS_HOSTCAPS_OFFSET (DXGK_VMBUS_VGPU_LUID_OFFSET + \ + sizeof(struct winluid)) + +/* The guest writes its capavilities to this adderss */ #define DXGK_VMBUS_GUESTCAPS_OFFSET (DXGK_VMBUS_VERSION_OFFSET + \ sizeof(u32)) @@ -441,6 +445,23 @@ struct dxgk_vmbus_guestcaps { }; }; +/* + * The structure defines features, supported by the host. + * + * map_guest_memory + * Host can map guest memory pages, so the guest can avoid using GPADLs + * to represent existing system memory allocations. + */ +struct dxgk_vmbus_hostcaps { + union { + struct { + u32 map_guest_memory : 1; + u32 reserved : 31; + }; + u32 host_caps; + }; +}; + /* * A helper function to read PCI config space. */ @@ -475,6 +496,7 @@ static int dxg_pci_probe_device(struct pci_dev *dev, struct winluid vgpu_luid = {}; struct dxgk_vmbus_guestcaps guest_caps = {.wsl2 = 1}; struct dxgglobal *dxgglobal = dxggbl(); + struct dxgk_vmbus_hostcaps host_caps = {}; mutex_lock(&dxgglobal->device_mutex); @@ -503,6 +525,13 @@ static int dxg_pci_probe_device(struct pci_dev *dev, if (ret) goto cleanup; + ret = pci_read_config_dword(dev, DXGK_VMBUS_HOSTCAPS_OFFSET, + &host_caps.host_caps); + if (ret == 0) { + if (host_caps.map_guest_memory) + dxgglobal->map_guest_pages_enabled = true; + } + if (dxgglobal->vmbus_ver > DXGK_VMBUS_INTERFACE_VERSION) dxgglobal->vmbus_ver = DXGK_VMBUS_INTERFACE_VERSION; } diff --git a/drivers/hv/dxgkrnl/dxgvmbus.c b/drivers/hv/dxgkrnl/dxgvmbus.c index 111111111111..222222222222 100644 --- a/drivers/hv/dxgkrnl/dxgvmbus.c +++ b/drivers/hv/dxgkrnl/dxgvmbus.c @@ -1383,15 +1383,19 @@ int create_existing_sysmem(struct dxgdevice *device, void *kmem = NULL; int ret = 0; struct dxgkvmb_command_setexistingsysmemstore *set_store_command; + struct dxgkvmb_command_setexistingsysmempages *set_pages_command; u64 alloc_size = host_alloc->allocation_size; u32 npages = alloc_size >> PAGE_SHIFT; struct dxgvmbusmsg msg = {.hdr = NULL}; - - ret = init_message(&msg, device->adapter, device->process, - sizeof(*set_store_command)); - if (ret) - goto cleanup; - set_store_command = (void *)msg.msg; + const u32 max_pfns_in_message = + (DXG_MAX_VM_BUS_PACKET_SIZE - sizeof(*set_pages_command) - + PAGE_SIZE) / sizeof(__u64); + u32 alloc_offset_in_pages = 0; + struct page **page_in; + u64 *pfn; + u32 pages_to_send; + u32 i; + struct dxgglobal *dxgglobal = dxggbl(); /* * Create a guest physical address list and set it as the allocation @@ -1402,6 +1406,7 @@ int create_existing_sysmem(struct dxgdevice *device, DXG_TRACE("Alloc size: %lld", alloc_size); dxgalloc->cpu_address = (void *)sysmem; + dxgalloc->pages = vzalloc(npages * sizeof(void *)); if (dxgalloc->pages == NULL) { DXG_ERR("failed to allocate pages"); @@ -1419,39 +1424,87 @@ int create_existing_sysmem(struct dxgdevice *device, ret = -ENOMEM; goto cleanup; } - kmem = vmap(dxgalloc->pages, npages, VM_MAP, PAGE_KERNEL); - if (kmem == NULL) { - DXG_ERR("vmap failed"); - ret = -ENOMEM; - goto cleanup; - } - ret1 = vmbus_establish_gpadl(dxgglobal_get_vmbus(), kmem, - alloc_size, &dxgalloc->gpadl); - if (ret1) { - DXG_ERR("establish_gpadl failed: %d", ret1); - ret = -ENOMEM; - goto cleanup; - } + if (!dxgglobal->map_guest_pages_enabled) { + ret = init_message(&msg, device->adapter, device->process, + sizeof(*set_store_command)); + if (ret) + goto cleanup; + set_store_command = (void *)msg.msg; + + kmem = vmap(dxgalloc->pages, npages, VM_MAP, PAGE_KERNEL); + if (kmem == NULL) { + DXG_ERR("vmap failed"); + ret = -ENOMEM; + goto cleanup; + } + ret1 = vmbus_establish_gpadl(dxgglobal_get_vmbus(), kmem, + alloc_size, &dxgalloc->gpadl); + if (ret1) { + DXG_ERR("establish_gpadl failed: %d", ret1); + ret = -ENOMEM; + goto cleanup; + } #ifdef _MAIN_KERNEL_ - DXG_TRACE("New gpadl %d", dxgalloc->gpadl.gpadl_handle); + DXG_TRACE("New gpadl %d", dxgalloc->gpadl.gpadl_handle); #else - DXG_TRACE("New gpadl %d", dxgalloc->gpadl); + DXG_TRACE("New gpadl %d", dxgalloc->gpadl); #endif - command_vgpu_to_host_init2(&set_store_command->hdr, - DXGK_VMBCOMMAND_SETEXISTINGSYSMEMSTORE, - device->process->host_handle); - set_store_command->device = device->handle; - set_store_command->device = device->handle; - set_store_command->allocation = host_alloc->allocation; + command_vgpu_to_host_init2(&set_store_command->hdr, + DXGK_VMBCOMMAND_SETEXISTINGSYSMEMSTORE, + device->process->host_handle); + set_store_command->device = device->handle; + set_store_command->allocation = host_alloc->allocation; #ifdef _MAIN_KERNEL_ - set_store_command->gpadl = dxgalloc->gpadl.gpadl_handle; + set_store_command->gpadl = dxgalloc->gpadl.gpadl_handle; #else - set_store_command->gpadl = dxgalloc->gpadl; + set_store_command->gpadl = dxgalloc->gpadl; #endif - ret = dxgvmb_send_sync_msg_ntstatus(msg.channel, msg.hdr, msg.size); - if (ret < 0) - DXG_ERR("failed to set existing store: %x", ret); + ret = dxgvmb_send_sync_msg_ntstatus(msg.channel, msg.hdr, + msg.size); + if (ret < 0) + DXG_ERR("failed set existing store: %x", ret); + } else { + /* + * Send the list of the allocation PFNs to the host. The host + * will map the pages for GPU access. + */ + + ret = init_message(&msg, device->adapter, device->process, + sizeof(*set_pages_command) + + max_pfns_in_message * sizeof(u64)); + if (ret) + goto cleanup; + set_pages_command = (void *)msg.msg; + command_vgpu_to_host_init2(&set_pages_command->hdr, + DXGK_VMBCOMMAND_SETEXISTINGSYSMEMPAGES, + device->process->host_handle); + set_pages_command->device = device->handle; + set_pages_command->allocation = host_alloc->allocation; + + page_in = dxgalloc->pages; + while (alloc_offset_in_pages < npages) { + pfn = (u64 *)((char *)msg.msg + + sizeof(*set_pages_command)); + pages_to_send = min(npages - alloc_offset_in_pages, + max_pfns_in_message); + set_pages_command->num_pages = pages_to_send; + set_pages_command->alloc_offset_in_pages = + alloc_offset_in_pages; + + for (i = 0; i < pages_to_send; i++) + *pfn++ = page_to_pfn(*page_in++); + + ret = dxgvmb_send_sync_msg_ntstatus(msg.channel, + msg.hdr, + msg.size); + if (ret < 0) { + DXG_ERR("failed set existing pages: %x", ret); + break; + } + alloc_offset_in_pages += pages_to_send; + } + } cleanup: if (kmem) diff --git a/drivers/hv/dxgkrnl/dxgvmbus.h b/drivers/hv/dxgkrnl/dxgvmbus.h index 111111111111..222222222222 100644 --- a/drivers/hv/dxgkrnl/dxgvmbus.h +++ b/drivers/hv/dxgkrnl/dxgvmbus.h @@ -234,6 +234,16 @@ struct dxgkvmb_command_setexistingsysmemstore { u32 gpadl; }; +/* Returns ntstatus */ +struct dxgkvmb_command_setexistingsysmempages { + struct dxgkvmb_command_vgpu_to_host hdr; + struct d3dkmthandle device; + struct d3dkmthandle allocation; + u32 num_pages; + u32 alloc_offset_in_pages; + /* u64 pfn_array[num_pages] */ +}; + struct dxgkvmb_command_createprocess { struct dxgkvmb_command_vm_to_host hdr; void *process; diff --git a/drivers/hv/dxgkrnl/misc.c b/drivers/hv/dxgkrnl/misc.c index 111111111111..222222222222 100644 --- a/drivers/hv/dxgkrnl/misc.c +++ b/drivers/hv/dxgkrnl/misc.c @@ -35,3 +35,4 @@ u16 *wcsncpy(u16 *dest, const u16 *src, size_t n) dest[i - 1] = 0; return dest; } + -- Armbian