From e3353d63e15d0b1109257d55e265a889e8c508f8 Mon Sep 17 00:00:00 2001 From: Steve Sistare Date: Mon, 19 May 2025 06:26:43 -0700 Subject: [PATCH] vfio: return mr from vfio_get_xlat_addr MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Modify memory_get_xlat_addr and vfio_get_xlat_addr to return the memory region that the translated address is found in. This will be needed by CPR in a subsequent patch to map blocks using IOMMU_IOAS_MAP_FILE. Also return the xlat offset, so we can simplify the interface by removing the out parameters that can be trivially derived from mr and xlat. Lastly, rename the functions to to memory_translate_iotlb() and vfio_translate_iotlb(). Signed-off-by: Steve Sistare Acked-by: David Hildenbrand Reviewed-by: Cédric Le Goater Reviewed-by: John Levon Acked-by: Michael S. Tsirkin Reviewed-by: Zhenzhong Duan Link: https://lore.kernel.org/qemu-devel/1747661203-136490-1-git-send-email-steven.sistare@oracle.com Signed-off-by: Cédric Le Goater --- hw/vfio/listener.c | 33 ++++++++++++++++++++++----------- hw/virtio/vhost-vdpa.c | 9 +++++++-- include/system/memory.h | 19 +++++++++---------- system/memory.c | 32 +++++++------------------------- 4 files changed, 45 insertions(+), 48 deletions(-) diff --git a/hw/vfio/listener.c b/hw/vfio/listener.c index bfacb3d8d9..38e3dc82cf 100644 --- a/hw/vfio/listener.c +++ b/hw/vfio/listener.c @@ -90,16 +90,17 @@ static bool vfio_listener_skipped_section(MemoryRegionSection *section) section->offset_within_address_space & (1ULL << 63); } -/* Called with rcu_read_lock held. */ -static bool vfio_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, - ram_addr_t *ram_addr, bool *read_only, - Error **errp) +/* + * Called with rcu_read_lock held. + * The returned MemoryRegion must not be accessed after calling rcu_read_unlock. + */ +static MemoryRegion *vfio_translate_iotlb(IOMMUTLBEntry *iotlb, hwaddr *xlat_p, + Error **errp) { - bool ret, mr_has_discard_manager; + MemoryRegion *mr; - ret = memory_get_xlat_addr(iotlb, vaddr, ram_addr, read_only, - &mr_has_discard_manager, errp); - if (ret && mr_has_discard_manager) { + mr = memory_translate_iotlb(iotlb, xlat_p, errp); + if (mr && memory_region_has_ram_discard_manager(mr)) { /* * Malicious VMs might trigger discarding of IOMMU-mapped memory. The * pages will remain pinned inside vfio until unmapped, resulting in a @@ -118,7 +119,7 @@ static bool vfio_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, " intended via an IOMMU. It's possible to mitigate " " by setting/adjusting RLIMIT_MEMLOCK."); } - return ret; + return mr; } static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) @@ -126,6 +127,8 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) VFIOGuestIOMMU *giommu = container_of(n, VFIOGuestIOMMU, n); VFIOContainerBase *bcontainer = giommu->bcontainer; hwaddr iova = iotlb->iova + giommu->iommu_offset; + MemoryRegion *mr; + hwaddr xlat; void *vaddr; int ret; Error *local_err = NULL; @@ -150,10 +153,14 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) { bool read_only; - if (!vfio_get_xlat_addr(iotlb, &vaddr, NULL, &read_only, &local_err)) { + mr = vfio_translate_iotlb(iotlb, &xlat, &local_err); + if (!mr) { error_report_err(local_err); goto out; } + vaddr = memory_region_get_ram_ptr(mr) + xlat; + read_only = !(iotlb->perm & IOMMU_WO) || mr->readonly; + /* * vaddr is only valid until rcu_read_unlock(). But after * vfio_dma_map has set up the mapping the pages will be @@ -1010,6 +1017,8 @@ static void vfio_iommu_map_dirty_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) ram_addr_t translated_addr; Error *local_err = NULL; int ret = -EINVAL; + MemoryRegion *mr; + hwaddr xlat; trace_vfio_iommu_map_dirty_notify(iova, iova + iotlb->addr_mask); @@ -1021,9 +1030,11 @@ static void vfio_iommu_map_dirty_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) } rcu_read_lock(); - if (!vfio_get_xlat_addr(iotlb, NULL, &translated_addr, NULL, &local_err)) { + mr = vfio_translate_iotlb(iotlb, &xlat, &local_err); + if (!mr) { goto out_unlock; } + translated_addr = memory_region_get_ram_addr(mr) + xlat; ret = vfio_container_query_dirty_bitmap(bcontainer, iova, iotlb->addr_mask + 1, translated_addr, &local_err); diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c index e20da95f30..7061b6e1a3 100644 --- a/hw/virtio/vhost-vdpa.c +++ b/hw/virtio/vhost-vdpa.c @@ -209,6 +209,8 @@ static void vhost_vdpa_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) int ret; Int128 llend; Error *local_err = NULL; + MemoryRegion *mr; + hwaddr xlat; if (iotlb->target_as != &address_space_memory) { error_report("Wrong target AS \"%s\", only system memory is allowed", @@ -228,11 +230,14 @@ static void vhost_vdpa_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) { bool read_only; - if (!memory_get_xlat_addr(iotlb, &vaddr, NULL, &read_only, NULL, - &local_err)) { + mr = memory_translate_iotlb(iotlb, &xlat, &local_err); + if (!mr) { error_report_err(local_err); return; } + vaddr = memory_region_get_ram_ptr(mr) + xlat; + read_only = !(iotlb->perm & IOMMU_WO) || mr->readonly; + ret = vhost_vdpa_dma_map(s, VHOST_VDPA_GUEST_PA_ASID, iova, iotlb->addr_mask + 1, vaddr, read_only); if (ret) { diff --git a/include/system/memory.h b/include/system/memory.h index fc35a0dcad..0848690ea4 100644 --- a/include/system/memory.h +++ b/include/system/memory.h @@ -739,21 +739,20 @@ void ram_discard_manager_unregister_listener(RamDiscardManager *rdm, RamDiscardListener *rdl); /** - * memory_get_xlat_addr: Extract addresses from a TLB entry + * memory_translate_iotlb: Extract addresses from a TLB entry. + * Called with rcu_read_lock held. * * @iotlb: pointer to an #IOMMUTLBEntry - * @vaddr: virtual address - * @ram_addr: RAM address - * @read_only: indicates if writes are allowed - * @mr_has_discard_manager: indicates memory is controlled by a - * RamDiscardManager + * @xlat_p: return the offset of the entry from the start of the returned + * MemoryRegion. * @errp: pointer to Error*, to store an error if it happens. * - * Return: true on success, else false setting @errp with error. + * Return: On success, return the MemoryRegion containing the @iotlb translated + * addr. The MemoryRegion must not be accessed after rcu_read_unlock. + * On failure, return NULL, setting @errp with error. */ -bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, - ram_addr_t *ram_addr, bool *read_only, - bool *mr_has_discard_manager, Error **errp); +MemoryRegion *memory_translate_iotlb(IOMMUTLBEntry *iotlb, hwaddr *xlat_p, + Error **errp); typedef struct CoalescedMemoryRange CoalescedMemoryRange; typedef struct MemoryRegionIoeventfd MemoryRegionIoeventfd; diff --git a/system/memory.c b/system/memory.c index 63b983efcd..306e9ff9eb 100644 --- a/system/memory.c +++ b/system/memory.c @@ -2174,18 +2174,14 @@ void ram_discard_manager_unregister_listener(RamDiscardManager *rdm, } /* Called with rcu_read_lock held. */ -bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, - ram_addr_t *ram_addr, bool *read_only, - bool *mr_has_discard_manager, Error **errp) +MemoryRegion *memory_translate_iotlb(IOMMUTLBEntry *iotlb, hwaddr *xlat_p, + Error **errp) { MemoryRegion *mr; hwaddr xlat; hwaddr len = iotlb->addr_mask + 1; bool writable = iotlb->perm & IOMMU_WO; - if (mr_has_discard_manager) { - *mr_has_discard_manager = false; - } /* * The IOMMU TLB entry we have just covers translation through * this IOMMU to its immediate target. We need to translate @@ -2195,7 +2191,7 @@ bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, &xlat, &len, writable, MEMTXATTRS_UNSPECIFIED); if (!memory_region_is_ram(mr)) { error_setg(errp, "iommu map to non memory area %" HWADDR_PRIx "", xlat); - return false; + return NULL; } else if (memory_region_has_ram_discard_manager(mr)) { RamDiscardManager *rdm = memory_region_get_ram_discard_manager(mr); MemoryRegionSection tmp = { @@ -2203,9 +2199,6 @@ bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, .offset_within_region = xlat, .size = int128_make64(len), }; - if (mr_has_discard_manager) { - *mr_has_discard_manager = true; - } /* * Malicious VMs can map memory into the IOMMU, which is expected * to remain discarded. vfio will pin all pages, populating memory. @@ -2216,7 +2209,7 @@ bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, error_setg(errp, "iommu map to discarded memory (e.g., unplugged" " via virtio-mem): %" HWADDR_PRIx "", iotlb->translated_addr); - return false; + return NULL; } } @@ -2226,22 +2219,11 @@ bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, */ if (len & iotlb->addr_mask) { error_setg(errp, "iommu has granularity incompatible with target AS"); - return false; - } - - if (vaddr) { - *vaddr = memory_region_get_ram_ptr(mr) + xlat; - } - - if (ram_addr) { - *ram_addr = memory_region_get_ram_addr(mr) + xlat; - } - - if (read_only) { - *read_only = !writable || mr->readonly; + return NULL; } - return true; + *xlat_p = xlat; + return mr; } void memory_region_set_log(MemoryRegion *mr, bool log, unsigned client) -- 2.39.5