This is a note to let you know that I've just added the patch titled
KVM: x86/mmu: Move TDP MMU VM init/uninit behind tdp_mmu_enabled
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-x86-mmu-move-tdp-mmu-vm-init-uninit-behind-tdp_m.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6c0200d18fba9cf801bc9b3a8b34b940ad3f347f
Author: David Matlack <dmatlack@xxxxxxxxxx>
Date: Wed Sep 21 10:35:38 2022 -0700
KVM: x86/mmu: Move TDP MMU VM init/uninit behind tdp_mmu_enabled
[ Upstream commit 991c8047b740f192a057d5f22df2f91f087cdb72 ]
Move kvm_mmu_{init,uninit}_tdp_mmu() behind tdp_mmu_enabled. This makes
these functions consistent with the rest of the calls into the TDP MMU
from mmu.c, and which is now possible since tdp_mmu_enabled is only
modified when the x86 vendor module is loaded. i.e. It will never change
during the lifetime of a VM.
This change also enabled removing the stub definitions for 32-bit KVM,
as the compiler will just optimize the calls out like it does for all
the other TDP MMU functions.
No functional change intended.
Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>
Reviewed-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Message-Id: <20220921173546.2674386-3-dmatlack@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Stable-dep-of: edbdb43fc96b ("KVM: x86: Preserve TDP MMU roots until they are explicitly invalidated")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 583979755bd4f..8666e8ff48a6e 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -6051,9 +6051,11 @@ int kvm_mmu_init_vm(struct kvm *kvm)
INIT_LIST_HEAD(&kvm->arch.possible_nx_huge_pages);
spin_lock_init(&kvm->arch.mmu_unsync_pages_lock);
- r = kvm_mmu_init_tdp_mmu(kvm);
- if (r < 0)
- return r;
+ if (tdp_mmu_enabled) {
+ r = kvm_mmu_init_tdp_mmu(kvm);
+ if (r < 0)
+ return r;
+ }
node->track_write = kvm_mmu_pte_write;
node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot;
@@ -6083,7 +6085,8 @@ void kvm_mmu_uninit_vm(struct kvm *kvm)
kvm_page_track_unregister_notifier(kvm, node);
- kvm_mmu_uninit_tdp_mmu(kvm);
+ if (tdp_mmu_enabled)
+ kvm_mmu_uninit_tdp_mmu(kvm);
mmu_free_vm_memory_caches(kvm);
}
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 03511e83050fa..7e5952e95d3bf 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -15,9 +15,6 @@ int kvm_mmu_init_tdp_mmu(struct kvm *kvm)
{
struct workqueue_struct *wq;
- if (!tdp_mmu_enabled)
- return 0;
-
wq = alloc_workqueue("kvm", WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 0);
if (!wq)
return -ENOMEM;
@@ -42,9 +39,6 @@ static __always_inline bool kvm_lockdep_assert_mmu_lock_held(struct kvm *kvm,
void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm)
{
- if (!tdp_mmu_enabled)
- return;
-
/* Also waits for any queued work items. */
destroy_workqueue(kvm->arch.tdp_mmu_zap_wq);
diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h
index d3714200b932a..e4ab2dac269d6 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.h
+++ b/arch/x86/kvm/mmu/tdp_mmu.h
@@ -7,6 +7,9 @@
#include "spte.h"
+int kvm_mmu_init_tdp_mmu(struct kvm *kvm);
+void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm);
+
hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu);
__must_check static inline bool kvm_tdp_mmu_get_root(struct kvm_mmu_page *root)
@@ -68,8 +71,6 @@ u64 *kvm_tdp_mmu_fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, u64 addr,
u64 *spte);
#ifdef CONFIG_X86_64
-int kvm_mmu_init_tdp_mmu(struct kvm *kvm);
-void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm);
static inline bool is_tdp_mmu_page(struct kvm_mmu_page *sp) { return sp->tdp_mmu_page; }
static inline bool is_tdp_mmu(struct kvm_mmu *mmu)
@@ -89,8 +90,6 @@ static inline bool is_tdp_mmu(struct kvm_mmu *mmu)
return sp && is_tdp_mmu_page(sp) && sp->root_count;
}
#else
-static inline int kvm_mmu_init_tdp_mmu(struct kvm *kvm) { return 0; }
-static inline void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm) {}
static inline bool is_tdp_mmu_page(struct kvm_mmu_page *sp) { return false; }
static inline bool is_tdp_mmu(struct kvm_mmu *mmu) { return false; }
#endif
