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>
This commit is contained in:
Stanislav Kinsburskii 2025-12-03 21:40:50 +00:00 committed by Wei Liu
parent 6f6aed2c49
commit e950c30a10
4 changed files with 198 additions and 165 deletions

View File

@ -14,7 +14,7 @@ hv_vmbus-y := vmbus_drv.o \
hv_vmbus-$(CONFIG_HYPERV_TESTING) += hv_debugfs.o
hv_utils-y := hv_util.o hv_kvp.o hv_snapshot.o hv_utils_transport.o
mshv_root-y := mshv_root_main.o mshv_synic.o mshv_eventfd.o mshv_irq.o \
mshv_root_hv_call.o mshv_portid_table.o
mshv_root_hv_call.o mshv_portid_table.o mshv_regions.o
mshv_vtl-y := mshv_vtl_main.o
# Code that must be built-in

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

View File

@ -312,4 +312,14 @@ extern struct mshv_root mshv_root;
extern enum hv_scheduler_type hv_scheduler_type;
extern u8 * __percpu *hv_synic_eventring_tail;
struct mshv_mem_region *mshv_region_create(u64 guest_pfn, u64 nr_pages,
u64 uaddr, u32 flags,
bool is_mmio);
int mshv_region_share(struct mshv_mem_region *region);
int mshv_region_unshare(struct mshv_mem_region *region);
int mshv_region_map(struct mshv_mem_region *region);
void mshv_region_invalidate(struct mshv_mem_region *region);
int mshv_region_pin(struct mshv_mem_region *region);
void mshv_region_destroy(struct mshv_mem_region *region);
#endif /* _MSHV_ROOT_H_ */

View File

@ -1059,117 +1059,6 @@ static void mshv_async_hvcall_handler(void *data, u64 *status)
*status = partition->async_hypercall_status;
}
static int
mshv_partition_region_share(struct mshv_mem_region *region)
{
u32 flags = HV_MODIFY_SPA_PAGE_HOST_ACCESS_MAKE_SHARED;
if (region->flags.large_pages)
flags |= HV_MODIFY_SPA_PAGE_HOST_ACCESS_LARGE_PAGE;
return hv_call_modify_spa_host_access(region->partition->pt_id,
region->pages, region->nr_pages,
HV_MAP_GPA_READABLE | HV_MAP_GPA_WRITABLE,
flags, true);
}
static int
mshv_partition_region_unshare(struct mshv_mem_region *region)
{
u32 flags = HV_MODIFY_SPA_PAGE_HOST_ACCESS_MAKE_EXCLUSIVE;
if (region->flags.large_pages)
flags |= HV_MODIFY_SPA_PAGE_HOST_ACCESS_LARGE_PAGE;
return hv_call_modify_spa_host_access(region->partition->pt_id,
region->pages, region->nr_pages,
0,
flags, false);
}
static int
mshv_region_remap_pages(struct mshv_mem_region *region, u32 map_flags,
u64 page_offset, u64 page_count)
{
if (page_offset + page_count > region->nr_pages)
return -EINVAL;
if (region->flags.large_pages)
map_flags |= HV_MAP_GPA_LARGE_PAGE;
/* ask the hypervisor to map guest ram */
return hv_call_map_gpa_pages(region->partition->pt_id,
region->start_gfn + page_offset,
page_count, map_flags,
region->pages + page_offset);
}
static int
mshv_region_map(struct mshv_mem_region *region)
{
u32 map_flags = region->hv_map_flags;
return mshv_region_remap_pages(region, map_flags,
0, region->nr_pages);
}
static void
mshv_region_invalidate_pages(struct mshv_mem_region *region,
u64 page_offset, u64 page_count)
{
if (region->flags.range_pinned)
unpin_user_pages(region->pages + page_offset, page_count);
memset(region->pages + page_offset, 0,
page_count * sizeof(struct page *));
}
static void
mshv_region_invalidate(struct mshv_mem_region *region)
{
mshv_region_invalidate_pages(region, 0, region->nr_pages);
}
static int
mshv_region_pin(struct mshv_mem_region *region)
{
u64 done_count, nr_pages;
struct page **pages;
__u64 userspace_addr;
int ret;
for (done_count = 0; done_count < region->nr_pages; done_count += ret) {
pages = region->pages + done_count;
userspace_addr = region->start_uaddr +
done_count * HV_HYP_PAGE_SIZE;
nr_pages = min(region->nr_pages - done_count,
MSHV_PIN_PAGES_BATCH_SIZE);
/*
* Pinning assuming 4k pages works for large pages too.
* All page structs within the large page are returned.
*
* Pin requests are batched because pin_user_pages_fast
* with the FOLL_LONGTERM flag does a large temporary
* allocation of contiguous memory.
*/
ret = pin_user_pages_fast(userspace_addr, nr_pages,
FOLL_WRITE | FOLL_LONGTERM,
pages);
if (ret < 0)
goto release_pages;
}
if (PageHuge(region->pages[0]))
region->flags.large_pages = true;
return 0;
release_pages:
mshv_region_invalidate_pages(region, 0, done_count);
return ret;
}
static struct mshv_mem_region *
mshv_partition_region_by_gfn(struct mshv_partition *partition, u64 gfn)
{
@ -1193,7 +1082,7 @@ static int mshv_partition_create_region(struct mshv_partition *partition,
struct mshv_mem_region **regionpp,
bool is_mmio)
{
struct mshv_mem_region *region, *rg;
struct mshv_mem_region *rg;
u64 nr_pages = HVPFN_DOWN(mem->size);
/* Reject overlapping regions */
@ -1205,26 +1094,15 @@ static int mshv_partition_create_region(struct mshv_partition *partition,
return -EEXIST;
}
region = vzalloc(sizeof(*region) + sizeof(struct page *) * nr_pages);
if (!region)
return -ENOMEM;
rg = mshv_region_create(mem->guest_pfn, nr_pages,
mem->userspace_addr, mem->flags,
is_mmio);
if (IS_ERR(rg))
return PTR_ERR(rg);
region->nr_pages = nr_pages;
region->start_gfn = mem->guest_pfn;
region->start_uaddr = mem->userspace_addr;
region->hv_map_flags = HV_MAP_GPA_READABLE | HV_MAP_GPA_ADJUSTABLE;
if (mem->flags & BIT(MSHV_SET_MEM_BIT_WRITABLE))
region->hv_map_flags |= HV_MAP_GPA_WRITABLE;
if (mem->flags & BIT(MSHV_SET_MEM_BIT_EXECUTABLE))
region->hv_map_flags |= HV_MAP_GPA_EXECUTABLE;
rg->partition = partition;
/* Note: large_pages flag populated when we pin the pages */
if (!is_mmio)
region->flags.range_pinned = true;
region->partition = partition;
*regionpp = region;
*regionpp = rg;
return 0;
}
@ -1262,7 +1140,7 @@ static int mshv_prepare_pinned_region(struct mshv_mem_region *region)
* access to guest memory regions.
*/
if (mshv_partition_encrypted(partition)) {
ret = mshv_partition_region_unshare(region);
ret = mshv_region_unshare(region);
if (ret) {
pt_err(partition,
"Failed to unshare memory region (guest_pfn: %llu): %d\n",
@ -1275,7 +1153,7 @@ static int mshv_prepare_pinned_region(struct mshv_mem_region *region)
if (ret && mshv_partition_encrypted(partition)) {
int shrc;
shrc = mshv_partition_region_share(region);
shrc = mshv_region_share(region);
if (!shrc)
goto invalidate_region;
@ -1356,36 +1234,6 @@ mshv_map_user_memory(struct mshv_partition *partition,
return ret;
}
static void mshv_partition_destroy_region(struct mshv_mem_region *region)
{
struct mshv_partition *partition = region->partition;
u32 unmap_flags = 0;
int ret;
hlist_del(&region->hnode);
if (mshv_partition_encrypted(partition)) {
ret = mshv_partition_region_share(region);
if (ret) {
pt_err(partition,
"Failed to regain access to memory, unpinning user pages will fail and crash the host error: %d\n",
ret);
return;
}
}
if (region->flags.large_pages)
unmap_flags |= HV_UNMAP_GPA_LARGE_PAGE;
/* ignore unmap failures and continue as process may be exiting */
hv_call_unmap_gpa_pages(partition->pt_id, region->start_gfn,
region->nr_pages, unmap_flags);
mshv_region_invalidate(region);
vfree(region);
}
/* Called for unmapping both the guest ram and the mmio space */
static long
mshv_unmap_user_memory(struct mshv_partition *partition,
@ -1406,7 +1254,7 @@ mshv_unmap_user_memory(struct mshv_partition *partition,
region->nr_pages != HVPFN_DOWN(mem.size))
return -EINVAL;
mshv_partition_destroy_region(region);
mshv_region_destroy(region);
return 0;
}
@ -1810,7 +1658,7 @@ static void destroy_partition(struct mshv_partition *partition)
hlist_for_each_entry_safe(region, n, &partition->pt_mem_regions,
hnode)
mshv_partition_destroy_region(region);
mshv_region_destroy(region);
/* Withdraw and free all pages we deposited */
hv_call_withdraw_memory(U64_MAX, NUMA_NO_NODE, partition->pt_id);