Using a similar two-step procedure as for memslots.
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Index: kvm-slotslock/arch/x86/include/asm/kvm_host.h
===================================================================
--- kvm-slotslock.orig/arch/x86/include/asm/kvm_host.h
+++ kvm-slotslock/arch/x86/include/asm/kvm_host.h
@@ -373,10 +373,13 @@ struct kvm_vcpu_arch {
u64 *mce_banks;
};
+#define KVM_ALIAS_INVALID 1UL
+
struct kvm_mem_alias {
gfn_t base_gfn;
unsigned long npages;
gfn_t target_gfn;
+ unsigned long flags;
};
struct kvm_mem_aliases {
Index: kvm-slotslock/arch/x86/kvm/mmu.c
===================================================================
--- kvm-slotslock.orig/arch/x86/kvm/mmu.c
+++ kvm-slotslock/arch/x86/kvm/mmu.c
@@ -424,7 +424,7 @@ static void account_shadowed(struct kvm
int *write_count;
int i;
- gfn = unalias_gfn(kvm, gfn);
+ gfn = unalias_gfn(kvm, gfn, false);
slot = gfn_to_memslot_unaliased(kvm, gfn);
for (i = PT_DIRECTORY_LEVEL;
@@ -440,7 +440,7 @@ static void unaccount_shadowed(struct kv
int *write_count;
int i;
- gfn = unalias_gfn(kvm, gfn);
+ gfn = unalias_gfn(kvm, gfn, false);
for (i = PT_DIRECTORY_LEVEL;
i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
slot = gfn_to_memslot_unaliased(kvm, gfn);
@@ -457,7 +457,7 @@ static int has_wrprotected_page(struct k
struct kvm_memory_slot *slot;
int *largepage_idx;
- gfn = unalias_gfn(kvm, gfn);
+ gfn = unalias_gfn(kvm, gfn, false);
slot = gfn_to_memslot_unaliased(kvm, gfn);
if (slot) {
largepage_idx = slot_largepage_idx(gfn, slot, level);
@@ -565,7 +565,7 @@ static int rmap_add(struct kvm_vcpu *vcp
if (!is_rmap_spte(*spte))
return count;
- gfn = unalias_gfn(vcpu->kvm, gfn);
+ gfn = unalias_gfn(vcpu->kvm, gfn, false);
sp = page_header(__pa(spte));
sp->gfns[spte - sp->spt] = gfn;
rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level);
@@ -703,7 +703,7 @@ static int rmap_write_protect(struct kvm
u64 *spte;
int i, write_protected = 0;
- gfn = unalias_gfn(kvm, gfn);
+ gfn = unalias_gfn(kvm, gfn, false);
rmapp = gfn_to_rmap(kvm, gfn, PT_PAGE_TABLE_LEVEL);
spte = rmap_next(kvm, rmapp, NULL);
@@ -836,7 +836,7 @@ static void rmap_recycle(struct kvm_vcpu
sp = page_header(__pa(spte));
- gfn = unalias_gfn(vcpu->kvm, gfn);
+ gfn = unalias_gfn(vcpu->kvm, gfn, false);
rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level);
kvm_unmap_rmapp(vcpu->kvm, rmapp);
@@ -3358,7 +3358,7 @@ static void audit_write_protection(struc
if (sp->unsync)
continue;
- gfn = unalias_gfn(vcpu->kvm, sp->gfn);
+ gfn = unalias_gfn(vcpu->kvm, sp->gfn, false);
slot = gfn_to_memslot_unaliased(vcpu->kvm, sp->gfn);
rmapp = &slot->rmap[gfn - slot->base_gfn];
Index: kvm-slotslock/arch/x86/kvm/x86.c
===================================================================
--- kvm-slotslock.orig/arch/x86/kvm/x86.c
+++ kvm-slotslock/arch/x86/kvm/x86.c
@@ -37,6 +37,7 @@
#include <linux/iommu.h>
#include <linux/intel-iommu.h>
#include <linux/cpufreq.h>
+#include <linux/srcu.h>
#include <trace/events/kvm.h>
#undef TRACE_INCLUDE_FILE
#define CREATE_TRACE_POINTS
@@ -1957,14 +1958,18 @@ static int kvm_vm_ioctl_get_nr_mmu_pages
return kvm->arch.n_alloc_mmu_pages;
}
-gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
+gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn, bool instantiation)
{
int i;
struct kvm_mem_alias *alias;
- struct kvm_mem_aliases *aliases = kvm->arch.aliases;
+ struct kvm_mem_aliases *aliases;
+
+ aliases = rcu_dereference(kvm->arch.aliases);
for (i = 0; i < aliases->naliases; ++i) {
alias = &aliases->aliases[i];
+ if (instantiation && (alias->flags & KVM_ALIAS_INVALID))
+ continue;
if (gfn >= alias->base_gfn
&& gfn < alias->base_gfn + alias->npages)
return alias->target_gfn + gfn - alias->base_gfn;
@@ -1982,7 +1987,7 @@ static int kvm_vm_ioctl_set_memory_alias
{
int r, n;
struct kvm_mem_alias *p;
- struct kvm_mem_aliases *aliases;
+ struct kvm_mem_aliases *aliases, *old_aliases;
r = -EINVAL;
/* General sanity checks */
@@ -1999,23 +2004,43 @@ static int kvm_vm_ioctl_set_memory_alias
< alias->target_phys_addr)
goto out;
+ r = -ENOMEM;
+ aliases = kzalloc(sizeof(struct kvm_mem_aliases), GFP_KERNEL);
+ if (!aliases)
+ goto out;
+
down_write(&kvm->slots_lock);
- spin_lock(&kvm->mmu_lock);
- aliases = kvm->arch.aliases;
+ /* invalidate any gfn reference in case of deletion/shrinking */
+ memcpy(aliases, kvm->arch.aliases, sizeof(struct kvm_mem_aliases));
+ aliases->aliases[alias->slot].flags |= KVM_ALIAS_INVALID;
+ old_aliases = kvm->arch.aliases;
+ rcu_assign_pointer(kvm->arch.aliases, aliases);
+ synchronize_srcu(&kvm->srcu);
+ kvm_mmu_zap_all(kvm);
+ kfree(old_aliases);
+
+ r = -ENOMEM;
+ aliases = kzalloc(sizeof(struct kvm_mem_aliases), GFP_KERNEL);
+ if (!aliases)
+ goto out;
+ memcpy(aliases, kvm->arch.aliases, sizeof(struct kvm_mem_aliases));
p = &aliases->aliases[alias->slot];
p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT;
p->npages = alias->memory_size >> PAGE_SHIFT;
p->target_gfn = alias->target_phys_addr >> PAGE_SHIFT;
+ p->flags &= ~(KVM_ALIAS_INVALID);
for (n = KVM_ALIAS_SLOTS; n > 0; --n)
if (aliases->aliases[n - 1].npages)
break;
aliases->naliases = n;
- spin_unlock(&kvm->mmu_lock);
- kvm_mmu_zap_all(kvm);
+ old_aliases = kvm->arch.aliases;
+ rcu_assign_pointer(kvm->arch.aliases, aliases);
+ synchronize_srcu(&kvm->srcu);
+ kfree(old_aliases);
up_write(&kvm->slots_lock);
Index: kvm-slotslock/include/linux/kvm_host.h
===================================================================
--- kvm-slotslock.orig/include/linux/kvm_host.h
+++ kvm-slotslock/include/linux/kvm_host.h
@@ -265,7 +265,7 @@ void kvm_arch_commit_memory_region(struc
int user_alloc);
void kvm_disable_largepages(void);
void kvm_arch_flush_shadow(struct kvm *kvm);
-gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn);
+gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn, bool instantiation);
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn);
unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn);
void kvm_release_page_clean(struct page *page);
Index: kvm-slotslock/virt/kvm/kvm_main.c
===================================================================
--- kvm-slotslock.orig/virt/kvm/kvm_main.c
+++ kvm-slotslock/virt/kvm/kvm_main.c
@@ -819,7 +819,7 @@ EXPORT_SYMBOL_GPL(gfn_to_memslot_unalias
struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
{
- gfn = unalias_gfn(kvm, gfn);
+ gfn = unalias_gfn(kvm, gfn, false);
return gfn_to_memslot_unaliased(kvm, gfn);
}
@@ -828,7 +828,7 @@ int kvm_is_visible_gfn(struct kvm *kvm,
int i;
struct kvm_memslots *slots = rcu_dereference(kvm->memslots);
- gfn = unalias_gfn(kvm, gfn);
+ gfn = unalias_gfn(kvm, gfn, true);
for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
struct kvm_memory_slot *memslot = &slots->memslots[i];
@@ -847,7 +847,7 @@ unsigned long gfn_to_hva(struct kvm *kvm
{
struct kvm_memory_slot *slot;
- gfn = unalias_gfn(kvm, gfn);
+ gfn = unalias_gfn(kvm, gfn, true);
slot = gfn_to_memslot_unaliased(kvm, gfn);
if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
return bad_hva();
@@ -1117,7 +1117,7 @@ void mark_page_dirty(struct kvm *kvm, gf
{
struct kvm_memory_slot *memslot;
- gfn = unalias_gfn(kvm, gfn);
+ gfn = unalias_gfn(kvm, gfn, false);
memslot = gfn_to_memslot_unaliased(kvm, gfn);
if (memslot && memslot->dirty_bitmap) {
unsigned long rel_gfn = gfn - memslot->base_gfn;
Index: kvm-slotslock/arch/ia64/kvm/kvm-ia64.c
===================================================================
--- kvm-slotslock.orig/arch/ia64/kvm/kvm-ia64.c
+++ kvm-slotslock/arch/ia64/kvm/kvm-ia64.c
@@ -1946,7 +1946,7 @@ int kvm_cpu_has_pending_timer(struct kvm
return vcpu->arch.timer_fired;
}
-gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
+gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn, bool instantiation)
{
return gfn;
}
Index: kvm-slotslock/arch/powerpc/kvm/powerpc.c
===================================================================
--- kvm-slotslock.orig/arch/powerpc/kvm/powerpc.c
+++ kvm-slotslock/arch/powerpc/kvm/powerpc.c
@@ -34,7 +34,7 @@
#define CREATE_TRACE_POINTS
#include "trace.h"
-gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
+gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn, bool instantiation)
{
return gfn;
}
Index: kvm-slotslock/arch/s390/kvm/kvm-s390.c
===================================================================
--- kvm-slotslock.orig/arch/s390/kvm/kvm-s390.c
+++ kvm-slotslock/arch/s390/kvm/kvm-s390.c
@@ -730,7 +730,7 @@ void kvm_arch_flush_shadow(struct kvm *k
{
}
-gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
+gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn, bool instantiation)
{
return gfn;
}
--
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