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authorSean Christopherson <seanjc@google.com>2023-10-27 21:22:04 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2023-11-14 16:01:05 +0300
commiteed52e434bc33603ddb0af62b6c4ef818948489d (patch)
tree0bf93687335ea9b38814f16182ca9a6f55a919a3 /include/linux/kvm_host.h
parent2333afa17af0f4b6651214ee17cfd5ae5f47787a (diff)
downloadlinux-eed52e434bc33603ddb0af62b6c4ef818948489d.tar.xz
KVM: Allow arch code to track number of memslot address spaces per VM
Let x86 track the number of address spaces on a per-VM basis so that KVM can disallow SMM memslots for confidential VMs. Confidentials VMs are fundamentally incompatible with emulating SMM, which as the name suggests requires being able to read and write guest memory and register state. Disallowing SMM will simplify support for guest private memory, as KVM will not need to worry about tracking memory attributes for multiple address spaces (SMM is the only "non-default" address space across all architectures). Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Message-Id: <20231027182217.3615211-23-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include/linux/kvm_host.h')
-rw-r--r--include/linux/kvm_host.h17
1 files changed, 11 insertions, 6 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index db423ea9e3a4..3ebc6912c54a 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -80,8 +80,8 @@
/* Two fragments for cross MMIO pages. */
#define KVM_MAX_MMIO_FRAGMENTS 2
-#ifndef KVM_ADDRESS_SPACE_NUM
-#define KVM_ADDRESS_SPACE_NUM 1
+#ifndef KVM_MAX_NR_ADDRESS_SPACES
+#define KVM_MAX_NR_ADDRESS_SPACES 1
#endif
/*
@@ -690,7 +690,12 @@ bool kvm_arch_irqchip_in_kernel(struct kvm *kvm);
#define KVM_MEM_SLOTS_NUM SHRT_MAX
#define KVM_USER_MEM_SLOTS (KVM_MEM_SLOTS_NUM - KVM_INTERNAL_MEM_SLOTS)
-#if KVM_ADDRESS_SPACE_NUM == 1
+#if KVM_MAX_NR_ADDRESS_SPACES == 1
+static inline int kvm_arch_nr_memslot_as_ids(struct kvm *kvm)
+{
+ return KVM_MAX_NR_ADDRESS_SPACES;
+}
+
static inline int kvm_arch_vcpu_memslots_id(struct kvm_vcpu *vcpu)
{
return 0;
@@ -745,9 +750,9 @@ struct kvm {
struct mm_struct *mm; /* userspace tied to this vm */
unsigned long nr_memslot_pages;
/* The two memslot sets - active and inactive (per address space) */
- struct kvm_memslots __memslots[KVM_ADDRESS_SPACE_NUM][2];
+ struct kvm_memslots __memslots[KVM_MAX_NR_ADDRESS_SPACES][2];
/* The current active memslot set for each address space */
- struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM];
+ struct kvm_memslots __rcu *memslots[KVM_MAX_NR_ADDRESS_SPACES];
struct xarray vcpu_array;
/*
* Protected by slots_lock, but can be read outside if an
@@ -1017,7 +1022,7 @@ void kvm_put_kvm_no_destroy(struct kvm *kvm);
static inline struct kvm_memslots *__kvm_memslots(struct kvm *kvm, int as_id)
{
- as_id = array_index_nospec(as_id, KVM_ADDRESS_SPACE_NUM);
+ as_id = array_index_nospec(as_id, KVM_MAX_NR_ADDRESS_SPACES);
return srcu_dereference_check(kvm->memslots[as_id], &kvm->srcu,
lockdep_is_held(&kvm->slots_lock) ||
!refcount_read(&kvm->users_count));