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Stanislav Kinsburskiiliuw
Stanislav Kinsburskii
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liuw
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mshv: Move region management to mshv_regions.c
Refactor memory region management functions from mshv_root_main.c into mshv_regions.c for better modularity and code organization. Adjust function calls and headers to use the new implementation. Improve maintainability and separation of concerns in the mshv_root module. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
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4 files changed

Lines changed: 198 additions & 165 deletions

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‎drivers/hv/Makefile‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -14,7 +14,7 @@ hv_vmbus-y := vmbus_drv.o \
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hv_vmbus-$(CONFIG_HYPERV_TESTING) += hv_debugfs.o
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hv_utils-y := hv_util.o hv_kvp.o hv_snapshot.o hv_utils_transport.o
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mshv_root-y := mshv_root_main.o mshv_synic.o mshv_eventfd.o mshv_irq.o \
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mshv_root_hv_call.o mshv_portid_table.o
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mshv_root_hv_call.o mshv_portid_table.o mshv_regions.o
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mshv_vtl-y := mshv_vtl_main.o
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2020
# Code that must be built-in

‎drivers/hv/mshv_regions.c‎

Lines changed: 175 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,175 @@
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2025, Microsoft Corporation.
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*
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* Memory region management for mshv_root module.
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*
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* Authors: Microsoft Linux virtualization team
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*/
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <asm/mshyperv.h>
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#include "mshv_root.h"
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struct mshv_mem_region *mshv_region_create(u64 guest_pfn, u64 nr_pages,
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u64 uaddr, u32 flags,
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bool is_mmio)
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{
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struct mshv_mem_region *region;
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region = vzalloc(sizeof(*region) + sizeof(struct page *) * nr_pages);
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if (!region)
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return ERR_PTR(-ENOMEM);
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region->nr_pages = nr_pages;
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region->start_gfn = guest_pfn;
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region->start_uaddr = uaddr;
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region->hv_map_flags = HV_MAP_GPA_READABLE | HV_MAP_GPA_ADJUSTABLE;
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if (flags & BIT(MSHV_SET_MEM_BIT_WRITABLE))
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region->hv_map_flags |= HV_MAP_GPA_WRITABLE;
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if (flags & BIT(MSHV_SET_MEM_BIT_EXECUTABLE))
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region->hv_map_flags |= HV_MAP_GPA_EXECUTABLE;
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/* Note: large_pages flag populated when we pin the pages */
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if (!is_mmio)
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region->flags.range_pinned = true;
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return region;
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}
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int mshv_region_share(struct mshv_mem_region *region)
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{
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u32 flags = HV_MODIFY_SPA_PAGE_HOST_ACCESS_MAKE_SHARED;
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if (region->flags.large_pages)
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flags |= HV_MODIFY_SPA_PAGE_HOST_ACCESS_LARGE_PAGE;
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return hv_call_modify_spa_host_access(region->partition->pt_id,
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region->pages, region->nr_pages,
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HV_MAP_GPA_READABLE | HV_MAP_GPA_WRITABLE,
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flags, true);
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}
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int mshv_region_unshare(struct mshv_mem_region *region)
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{
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u32 flags = HV_MODIFY_SPA_PAGE_HOST_ACCESS_MAKE_EXCLUSIVE;
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if (region->flags.large_pages)
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flags |= HV_MODIFY_SPA_PAGE_HOST_ACCESS_LARGE_PAGE;
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return hv_call_modify_spa_host_access(region->partition->pt_id,
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region->pages, region->nr_pages,
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0,
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flags, false);
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}
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static int mshv_region_remap_pages(struct mshv_mem_region *region,
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u32 map_flags,
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u64 page_offset, u64 page_count)
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{
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if (page_offset + page_count > region->nr_pages)
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return -EINVAL;
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if (region->flags.large_pages)
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map_flags |= HV_MAP_GPA_LARGE_PAGE;
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return hv_call_map_gpa_pages(region->partition->pt_id,
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region->start_gfn + page_offset,
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page_count, map_flags,
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region->pages + page_offset);
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}
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int mshv_region_map(struct mshv_mem_region *region)
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{
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u32 map_flags = region->hv_map_flags;
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return mshv_region_remap_pages(region, map_flags,
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0, region->nr_pages);
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}
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static void mshv_region_invalidate_pages(struct mshv_mem_region *region,
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u64 page_offset, u64 page_count)
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{
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if (region->flags.range_pinned)
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unpin_user_pages(region->pages + page_offset, page_count);
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memset(region->pages + page_offset, 0,
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page_count * sizeof(struct page *));
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}
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void mshv_region_invalidate(struct mshv_mem_region *region)
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{
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mshv_region_invalidate_pages(region, 0, region->nr_pages);
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}
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int mshv_region_pin(struct mshv_mem_region *region)
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{
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u64 done_count, nr_pages;
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struct page **pages;
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__u64 userspace_addr;
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int ret;
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for (done_count = 0; done_count < region->nr_pages; done_count += ret) {
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pages = region->pages + done_count;
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userspace_addr = region->start_uaddr +
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done_count * HV_HYP_PAGE_SIZE;
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nr_pages = min(region->nr_pages - done_count,
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MSHV_PIN_PAGES_BATCH_SIZE);
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/*
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* Pinning assuming 4k pages works for large pages too.
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* All page structs within the large page are returned.
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*
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* Pin requests are batched because pin_user_pages_fast
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* with the FOLL_LONGTERM flag does a large temporary
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* allocation of contiguous memory.
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*/
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ret = pin_user_pages_fast(userspace_addr, nr_pages,
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FOLL_WRITE | FOLL_LONGTERM,
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pages);
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if (ret < 0)
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goto release_pages;
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}
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if (PageHuge(region->pages[0]))
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region->flags.large_pages = true;
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return 0;
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release_pages:
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mshv_region_invalidate_pages(region, 0, done_count);
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return ret;
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}
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void mshv_region_destroy(struct mshv_mem_region *region)
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{
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struct mshv_partition *partition = region->partition;
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u32 unmap_flags = 0;
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int ret;
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hlist_del(&region->hnode);
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if (mshv_partition_encrypted(partition)) {
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ret = mshv_region_share(region);
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if (ret) {
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pt_err(partition,
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"Failed to regain access to memory, unpinning user pages will fail and crash the host error: %d\n",
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ret);
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return;
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}
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}
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if (region->flags.large_pages)
166+
unmap_flags |= HV_UNMAP_GPA_LARGE_PAGE;
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/* ignore unmap failures and continue as process may be exiting */
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hv_call_unmap_gpa_pages(partition->pt_id, region->start_gfn,
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region->nr_pages, unmap_flags);
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mshv_region_invalidate(region);
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vfree(region);
175+
}

‎drivers/hv/mshv_root.h‎

Lines changed: 10 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -312,4 +312,14 @@ extern struct mshv_root mshv_root;
312312
extern enum hv_scheduler_type hv_scheduler_type;
313313
extern u8 * __percpu *hv_synic_eventring_tail;
314314

315+
struct mshv_mem_region *mshv_region_create(u64 guest_pfn, u64 nr_pages,
316+
u64 uaddr, u32 flags,
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bool is_mmio);
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int mshv_region_share(struct mshv_mem_region *region);
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int mshv_region_unshare(struct mshv_mem_region *region);
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int mshv_region_map(struct mshv_mem_region *region);
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void mshv_region_invalidate(struct mshv_mem_region *region);
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int mshv_region_pin(struct mshv_mem_region *region);
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void mshv_region_destroy(struct mshv_mem_region *region);
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315325
#endif /* _MSHV_ROOT_H_ */

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