mirror of
https://github.com/torvalds/linux.git
synced 2026-10-17 05:14:17 +02:00
19192a4043
Move all code from s390_kvm_mmu_commit_memory_region() into
s390_kvm_mmu_prepare_memory_region(). This allows the function to fail
gracefully if needed. The previous behaviour was to print a warning and
continue execution with page tables inconsistent with the memslots.
Fixes: e38c884df9 ("KVM: s390: Switch to new gmap")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260828115439.145885-6-imbrenda@linux.ibm.com>
117 lines
3.1 KiB
C
117 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
#include <linux/kvm_types.h>
|
|
#include <linux/kvm_host.h>
|
|
|
|
#include "s390.h"
|
|
#include "gmap.h"
|
|
#include "dat.h"
|
|
#include "kvm_mmu.h"
|
|
|
|
/*
|
|
* Get (and clear) the dirty memory log for a memory slot.
|
|
*/
|
|
int s390_kvm_mmu_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
|
|
{
|
|
int r;
|
|
unsigned long n;
|
|
struct kvm_memory_slot *memslot;
|
|
int is_dirty;
|
|
|
|
if (kvm_is_ucontrol(kvm))
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&kvm->slots_lock);
|
|
|
|
r = -EINVAL;
|
|
if (log->slot >= KVM_USER_MEM_SLOTS)
|
|
goto out;
|
|
|
|
r = kvm_get_dirty_log(kvm, log, &is_dirty, &memslot);
|
|
if (r)
|
|
goto out;
|
|
|
|
/* Clear the dirty log */
|
|
if (is_dirty) {
|
|
n = kvm_dirty_bitmap_bytes(memslot);
|
|
memset(memslot->dirty_bitmap, 0, n);
|
|
}
|
|
r = 0;
|
|
out:
|
|
mutex_unlock(&kvm->slots_lock);
|
|
return r;
|
|
}
|
|
|
|
int s390_kvm_mmu_prepare_memory_region(struct kvm *kvm,
|
|
const struct kvm_memory_slot *old,
|
|
struct kvm_memory_slot *new,
|
|
enum kvm_mr_change change)
|
|
{
|
|
struct kvm_s390_mmu_cache *mc __free(kvm_s390_mmu_cache) = NULL;
|
|
int rc = 0;
|
|
|
|
if (kvm_is_ucontrol(kvm) && new && new->id < KVM_USER_MEM_SLOTS)
|
|
return -EINVAL;
|
|
|
|
/* When we are protected, we should not change the memory slots */
|
|
if (kvm_s390_pv_get_handle(kvm))
|
|
return -EINVAL;
|
|
|
|
if (change != KVM_MR_DELETE && change != KVM_MR_FLAGS_ONLY) {
|
|
/*
|
|
* A few sanity checks. The memory in userland is ok to be
|
|
* fragmented into various different vmas. It is okay to mmap()
|
|
* and munmap() stuff in this slot after doing this call at any
|
|
* time.
|
|
*/
|
|
if (change != KVM_MR_MOVE && change != KVM_MR_CREATE) {
|
|
WARN(1, "Unknown KVM MR CHANGE: %d\n", change);
|
|
return -EINVAL;
|
|
}
|
|
if (new->userspace_addr & ~PAGE_MASK)
|
|
return -EINVAL;
|
|
if ((new->base_gfn + new->npages) * PAGE_SIZE > kvm->arch.mem_limit)
|
|
return -EINVAL;
|
|
if (!asce_contains_gfn(kvm->arch.gmap->asce, new->base_gfn + new->npages - 1))
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (kvm->arch.migration_mode) {
|
|
/*
|
|
* Turn off migration mode when:
|
|
* - userspace creates a new memslot with dirty logging off,
|
|
* - userspace modifies an existing memslot (MOVE or FLAGS_ONLY)
|
|
* and dirty logging is turned off.
|
|
* Migration mode expects dirty page logging being enabled to
|
|
* store its dirty bitmap.
|
|
*/
|
|
if (change != KVM_MR_DELETE &&
|
|
!(new->flags & KVM_MEM_LOG_DIRTY_PAGES))
|
|
WARN(kvm_s390_vm_stop_migration(kvm),
|
|
"Failed to stop migration mode");
|
|
}
|
|
|
|
if (change == KVM_MR_FLAGS_ONLY)
|
|
return 0;
|
|
if (change != KVM_MR_DELETE) {
|
|
/* Enough capacity to add a new memslot */
|
|
mc = kvm_s390_new_mmu_cache();
|
|
if (!mc)
|
|
return -ENOMEM;
|
|
}
|
|
scoped_guard(write_lock, &kvm->mmu_lock) {
|
|
kvm_s390_update_cmma_dirty(kvm, old);
|
|
if (change == KVM_MR_DELETE || change == KVM_MR_MOVE)
|
|
rc = dat_delete_slot(kvm->arch.gmap->asce, old->base_gfn, old->npages);
|
|
if (!rc && (change == KVM_MR_MOVE || change == KVM_MR_CREATE))
|
|
rc = dat_create_slot(mc, kvm->arch.gmap->asce, new->base_gfn, new->npages);
|
|
}
|
|
/*
|
|
* Can only be triggered if dat_{create,delete}_slot() found an
|
|
* internal inconsistency or if the mmu cache ran out of memory;
|
|
* both should be impossible.
|
|
*/
|
|
KVM_BUG_ON(rc, kvm);
|
|
return rc;
|
|
}
|