From baa44bce87fe53ef5c95d39e634b3bace014d235 Mon Sep 17 00:00:00 2001 From: Cindy Lu Date: Mon, 31 Oct 2022 11:10:19 +0800 Subject: [PATCH] vfio: move implement of vfio_get_xlat_addr() to memory.c - Move the implement vfio_get_xlat_addr to softmmu/memory.c, and change the name to memory_get_xlat_addr(). So we can use this function on other devices, such as vDPA device. - Add a new function vfio_get_xlat_addr in vfio/common.c, and it will check whether the memory is backed by a discard manager. then device can have its own warning. Signed-off-by: Cindy Lu Message-Id: <20221031031020.1405111-2-lulu@redhat.com> Acked-by: Alex Williamson Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/vfio/common.c | 66 ++++------------------------------------------ include/exec/memory.h | 4 +++ softmmu/memory.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+), 61 deletions(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 6b5d8c0bf6..130e5d1dc7 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -578,45 +578,11 @@ static bool vfio_listener_skipped_section(MemoryRegionSection *section) static bool vfio_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, ram_addr_t *ram_addr, bool *read_only) { - MemoryRegion *mr; - hwaddr xlat; - hwaddr len = iotlb->addr_mask + 1; - bool writable = iotlb->perm & IOMMU_WO; - - /* - * The IOMMU TLB entry we have just covers translation through - * this IOMMU to its immediate target. We need to translate - * it the rest of the way through to memory. - */ - mr = address_space_translate(&address_space_memory, - iotlb->translated_addr, - &xlat, &len, writable, - MEMTXATTRS_UNSPECIFIED); - if (!memory_region_is_ram(mr)) { - error_report("iommu map to non memory area %"HWADDR_PRIx"", - xlat); - return false; - } else if (memory_region_has_ram_discard_manager(mr)) { - RamDiscardManager *rdm = memory_region_get_ram_discard_manager(mr); - MemoryRegionSection tmp = { - .mr = mr, - .offset_within_region = xlat, - .size = int128_make64(len), - }; - - /* - * Malicious VMs can map memory into the IOMMU, which is expected - * to remain discarded. vfio will pin all pages, populating memory. - * Disallow that. vmstate priorities make sure any RamDiscardManager - * were already restored before IOMMUs are restored. - */ - if (!ram_discard_manager_is_populated(rdm, &tmp)) { - error_report("iommu map to discarded memory (e.g., unplugged via" - " virtio-mem): %"HWADDR_PRIx"", - iotlb->translated_addr); - return false; - } + bool ret, mr_has_discard_manager; + ret = memory_get_xlat_addr(iotlb, vaddr, ram_addr, read_only, + &mr_has_discard_manager); + if (ret && mr_has_discard_manager) { /* * Malicious VMs might trigger discarding of IOMMU-mapped memory. The * pages will remain pinned inside vfio until unmapped, resulting in a @@ -635,29 +601,7 @@ static bool vfio_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, " intended via an IOMMU. It's possible to mitigate " " by setting/adjusting RLIMIT_MEMLOCK."); } - - /* - * Translation truncates length to the IOMMU page size, - * check that it did not truncate too much. - */ - if (len & iotlb->addr_mask) { - error_report("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 true; + return ret; } static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) diff --git a/include/exec/memory.h b/include/exec/memory.h index bfb1de8eea..d1e79c39dc 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -713,6 +713,10 @@ void ram_discard_manager_register_listener(RamDiscardManager *rdm, void ram_discard_manager_unregister_listener(RamDiscardManager *rdm, RamDiscardListener *rdl); +bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, + ram_addr_t *ram_addr, bool *read_only, + bool *mr_has_discard_manager); + typedef struct CoalescedMemoryRange CoalescedMemoryRange; typedef struct MemoryRegionIoeventfd MemoryRegionIoeventfd; diff --git a/softmmu/memory.c b/softmmu/memory.c index 7ba2048836..bc0be3f62c 100644 --- a/softmmu/memory.c +++ b/softmmu/memory.c @@ -33,6 +33,7 @@ #include "qemu/accel.h" #include "hw/boards.h" #include "migration/vmstate.h" +#include "exec/address-spaces.h" //#define DEBUG_UNASSIGNED @@ -2121,6 +2122,77 @@ void ram_discard_manager_unregister_listener(RamDiscardManager *rdm, rdmc->unregister_listener(rdm, rdl); } +/* 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) +{ + 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 + * it the rest of the way through to memory. + */ + mr = address_space_translate(&address_space_memory, iotlb->translated_addr, + &xlat, &len, writable, MEMTXATTRS_UNSPECIFIED); + if (!memory_region_is_ram(mr)) { + error_report("iommu map to non memory area %" HWADDR_PRIx "", xlat); + return false; + } else if (memory_region_has_ram_discard_manager(mr)) { + RamDiscardManager *rdm = memory_region_get_ram_discard_manager(mr); + MemoryRegionSection tmp = { + .mr = mr, + .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. + * Disallow that. vmstate priorities make sure any RamDiscardManager + * were already restored before IOMMUs are restored. + */ + if (!ram_discard_manager_is_populated(rdm, &tmp)) { + error_report("iommu map to discarded memory (e.g., unplugged via" + " virtio-mem): %" HWADDR_PRIx "", + iotlb->translated_addr); + return false; + } + } + + /* + * Translation truncates length to the IOMMU page size, + * check that it did not truncate too much. + */ + if (len & iotlb->addr_mask) { + error_report("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 true; +} + void memory_region_set_log(MemoryRegion *mr, bool log, unsigned client) { uint8_t mask = 1 << client; -- 2.11.4.GIT