diff options
| -rw-r--r-- | drivers/vfio/pci/nvgrace-gpu/main.c | 103 | ||||
| -rw-r--r-- | drivers/vfio/pci/vfio_pci_config.c | 1 | ||||
| -rw-r--r-- | drivers/vfio/pci/vfio_pci_priv.h | 1 | ||||
| -rw-r--r-- | include/linux/vfio_pci_core.h | 1 |
4 files changed, 93 insertions, 13 deletions
diff --git a/drivers/vfio/pci/nvgrace-gpu/main.c b/drivers/vfio/pci/nvgrace-gpu/main.c index df360e12b299..84d142a47ec6 100644 --- a/drivers/vfio/pci/nvgrace-gpu/main.c +++ b/drivers/vfio/pci/nvgrace-gpu/main.c @@ -8,6 +8,7 @@ #include <linux/delay.h> #include <linux/jiffies.h> #include <linux/pci-p2pdma.h> +#include <linux/pm_runtime.h> /* * The device memory usable to the workloads running in the VM is cached @@ -105,6 +106,19 @@ static int nvgrace_gpu_open_device(struct vfio_device *core_vdev) mutex_init(&nvdev->remap_lock); } + /* + * GPU readiness is checked by reading the BAR0 registers. + * + * ioremap BAR0 to ensure that the BAR0 mapping is present before + * register reads on first fault before establishing any GPU + * memory mapping. + */ + ret = vfio_pci_core_setup_barmap(vdev, 0); + if (ret) { + vfio_pci_core_disable(vdev); + return ret; + } + vfio_pci_core_finish_enable(vdev); return 0; @@ -147,6 +161,34 @@ static int nvgrace_gpu_wait_device_ready(void __iomem *io) return -ETIME; } +/* + * If the GPU memory is accessed by the CPU while the GPU is not ready + * after reset, it can cause harmless corrected RAS events to be logged. + * Make sure the GPU is ready before establishing the mappings. + */ +static int +nvgrace_gpu_check_device_ready(struct nvgrace_gpu_pci_core_device *nvdev) +{ + struct vfio_pci_core_device *vdev = &nvdev->core_device; + int ret; + + lockdep_assert_held_read(&vdev->memory_lock); + + if (!nvdev->reset_done) + return 0; + + if (!__vfio_pci_memory_enabled(vdev)) + return -EIO; + + ret = nvgrace_gpu_wait_device_ready(vdev->barmap[0]); + if (ret) + return ret; + + nvdev->reset_done = false; + + return 0; +} + static unsigned long addr_to_pgoff(struct vm_area_struct *vma, unsigned long addr) { @@ -176,8 +218,13 @@ static vm_fault_t nvgrace_gpu_vfio_pci_huge_fault(struct vm_fault *vmf, pfn = PHYS_PFN(memregion->memphys) + addr_to_pgoff(vma, addr); if (is_aligned_for_order(vma, addr, pfn, order)) { - scoped_guard(rwsem_read, &vdev->memory_lock) + scoped_guard(rwsem_read, &vdev->memory_lock) { + if (vdev->pm_runtime_engaged || + nvgrace_gpu_check_device_ready(nvdev)) + return VM_FAULT_SIGBUS; + ret = vfio_pci_vmf_insert_pfn(vdev, vmf, pfn, order); + } } dev_dbg_ratelimited(&vdev->pdev->dev, @@ -533,6 +580,7 @@ static ssize_t nvgrace_gpu_read_mem(struct nvgrace_gpu_pci_core_device *nvdev, char __user *buf, size_t count, loff_t *ppos) { + struct vfio_pci_core_device *vdev = &nvdev->core_device; u64 offset = *ppos & VFIO_PCI_OFFSET_MASK; unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos); struct mem_region *memregion; @@ -559,9 +607,15 @@ nvgrace_gpu_read_mem(struct nvgrace_gpu_pci_core_device *nvdev, else mem_count = min(count, memregion->memlength - (size_t)offset); - ret = nvgrace_gpu_map_and_read(nvdev, buf, mem_count, ppos); - if (ret) - return ret; + scoped_guard(rwsem_read, &vdev->memory_lock) { + ret = nvgrace_gpu_check_device_ready(nvdev); + if (ret) + return ret; + + ret = nvgrace_gpu_map_and_read(nvdev, buf, mem_count, ppos); + if (ret) + return ret; + } /* * Only the device memory present on the hardware is mapped, which may @@ -586,9 +640,16 @@ nvgrace_gpu_read(struct vfio_device *core_vdev, struct nvgrace_gpu_pci_core_device *nvdev = container_of(core_vdev, struct nvgrace_gpu_pci_core_device, core_device.vdev); + struct vfio_pci_core_device *vdev = &nvdev->core_device; + int ret; - if (nvgrace_gpu_memregion(index, nvdev)) - return nvgrace_gpu_read_mem(nvdev, buf, count, ppos); + if (nvgrace_gpu_memregion(index, nvdev)) { + if (pm_runtime_resume_and_get(&vdev->pdev->dev)) + return -EIO; + ret = nvgrace_gpu_read_mem(nvdev, buf, count, ppos); + pm_runtime_put(&vdev->pdev->dev); + return ret; + } if (index == VFIO_PCI_CONFIG_REGION_INDEX) return nvgrace_gpu_read_config_emu(core_vdev, buf, count, ppos); @@ -650,6 +711,7 @@ static ssize_t nvgrace_gpu_write_mem(struct nvgrace_gpu_pci_core_device *nvdev, size_t count, loff_t *ppos, const char __user *buf) { + struct vfio_pci_core_device *vdev = &nvdev->core_device; unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos); u64 offset = *ppos & VFIO_PCI_OFFSET_MASK; struct mem_region *memregion; @@ -679,9 +741,15 @@ nvgrace_gpu_write_mem(struct nvgrace_gpu_pci_core_device *nvdev, */ mem_count = min(count, memregion->memlength - (size_t)offset); - ret = nvgrace_gpu_map_and_write(nvdev, buf, mem_count, ppos); - if (ret) - return ret; + scoped_guard(rwsem_read, &vdev->memory_lock) { + ret = nvgrace_gpu_check_device_ready(nvdev); + if (ret) + return ret; + + ret = nvgrace_gpu_map_and_write(nvdev, buf, mem_count, ppos); + if (ret) + return ret; + } exitfn: *ppos += count; @@ -695,10 +763,17 @@ nvgrace_gpu_write(struct vfio_device *core_vdev, struct nvgrace_gpu_pci_core_device *nvdev = container_of(core_vdev, struct nvgrace_gpu_pci_core_device, core_device.vdev); + struct vfio_pci_core_device *vdev = &nvdev->core_device; unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos); + int ret; - if (nvgrace_gpu_memregion(index, nvdev)) - return nvgrace_gpu_write_mem(nvdev, count, ppos, buf); + if (nvgrace_gpu_memregion(index, nvdev)) { + if (pm_runtime_resume_and_get(&vdev->pdev->dev)) + return -EIO; + ret = nvgrace_gpu_write_mem(nvdev, count, ppos, buf); + pm_runtime_put(&vdev->pdev->dev); + return ret; + } if (index == VFIO_PCI_CONFIG_REGION_INDEX) return nvgrace_gpu_write_config_emu(core_vdev, buf, count, ppos); @@ -1074,7 +1149,11 @@ MODULE_DEVICE_TABLE(pci, nvgrace_gpu_vfio_pci_table); * faults and read/writes accesses to prevent potential RAS events logging. * * First fault or access after a reset needs to poll device readiness, - * flag that a reset has occurred. + * flag that a reset has occurred. The readiness test is done by holding + * the memory_lock read lock and we expect all vfio-pci initiated resets to + * hold the memory_lock write lock to avoid races. However, .reset_done + * extends beyond the scope of vfio-pci initiated resets therefore we + * cannot assert this behavior and use lockdep_assert_held_write. */ static void nvgrace_gpu_vfio_pci_reset_done(struct pci_dev *pdev) { diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c index 1f6008eabf23..dc4e510e6e1b 100644 --- a/drivers/vfio/pci/vfio_pci_config.c +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -416,6 +416,7 @@ bool __vfio_pci_memory_enabled(struct vfio_pci_core_device *vdev) return pdev->current_state < PCI_D3hot && (pdev->no_command_memory || (cmd & PCI_COMMAND_MEMORY)); } +EXPORT_SYMBOL_GPL(__vfio_pci_memory_enabled); /* * Restore the *real* BARs after we detect a FLR or backdoor reset. diff --git a/drivers/vfio/pci/vfio_pci_priv.h b/drivers/vfio/pci/vfio_pci_priv.h index 6681389518a7..27ac280f00b9 100644 --- a/drivers/vfio/pci/vfio_pci_priv.h +++ b/drivers/vfio/pci/vfio_pci_priv.h @@ -64,7 +64,6 @@ void vfio_config_free(struct vfio_pci_core_device *vdev); int vfio_pci_set_power_state(struct vfio_pci_core_device *vdev, pci_power_t state); -bool __vfio_pci_memory_enabled(struct vfio_pci_core_device *vdev); void vfio_pci_zap_and_down_write_memory_lock(struct vfio_pci_core_device *vdev); u16 vfio_pci_memory_lock_and_enable(struct vfio_pci_core_device *vdev); void vfio_pci_memory_unlock_and_restore(struct vfio_pci_core_device *vdev, diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h index 5569488ec4dc..336a0e58b443 100644 --- a/include/linux/vfio_pci_core.h +++ b/include/linux/vfio_pci_core.h @@ -188,6 +188,7 @@ ssize_t vfio_pci_core_do_io_rw(struct vfio_pci_core_device *vdev, bool test_mem, void __iomem *io, char __user *buf, loff_t off, size_t count, size_t x_start, size_t x_end, bool iswrite); +bool __vfio_pci_memory_enabled(struct vfio_pci_core_device *vdev); bool vfio_pci_core_range_intersect_range(loff_t buf_start, size_t buf_cnt, loff_t reg_start, size_t reg_cnt, loff_t *buf_offset, |