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authorLinus Torvalds <torvalds@linux-foundation.org>2018-01-12 09:56:52 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-01-12 09:56:52 -0800
commit4e67483a6f6f08b96a5e8833f3587c1255b08add (patch)
treed63b256beb32c2d6adcee35ed5264f42c53c7098
parent70cd9071e8fbe5eb88e02891bccfe20ae1f52630 (diff)
parent2aad9b3e0711f8c67c472920cd5b70199fba8520 (diff)
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini: "PPC: - user-triggerable use-after-free in HPT resizing - stale TLB entries in the guest - trap-and-emulate (PR) KVM guests failing to start under pHyp x86: - Another "Spectre" fix. - async pagefault fix - Revert an old fix for x86 nested virtualization, which turned out to do more harm than good - Check shrinker registration return code, to avoid warnings from upcoming 4.16 -mm patches" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Add memory barrier on vmcs field lookup KVM: x86: emulate #UD while in guest mode x86: kvm: propagate register_shrinker return code KVM MMU: check pending exception before injecting APF KVM: PPC: Book3S HV: Always flush TLB in kvmppc_alloc_reset_hpt() KVM: PPC: Book3S PR: Fix WIMG handling under pHyp KVM: PPC: Book3S HV: Fix use after free in case of multiple resize requests KVM: PPC: Book3S HV: Drop prepare_done from struct kvm_resize_hpt
-rw-r--r--arch/powerpc/kvm/book3s_64_mmu.c1
-rw-r--r--arch/powerpc/kvm/book3s_64_mmu_hv.c90
-rw-r--r--arch/powerpc/kvm/book3s_pr.c2
-rw-r--r--arch/x86/kvm/mmu.c19
-rw-r--r--arch/x86/kvm/svm.c9
-rw-r--r--arch/x86/kvm/vmx.c17
6 files changed, 88 insertions, 50 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c
index 29ebe2fd5867..a93d719edc90 100644
--- a/arch/powerpc/kvm/book3s_64_mmu.c
+++ b/arch/powerpc/kvm/book3s_64_mmu.c
@@ -235,6 +235,7 @@ static int kvmppc_mmu_book3s_64_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
gpte->may_read = true;
gpte->may_write = true;
gpte->page_size = MMU_PAGE_4K;
+ gpte->wimg = HPTE_R_M;
return 0;
}
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 966097232d21..b73dbc9e797d 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -65,11 +65,17 @@ struct kvm_resize_hpt {
u32 order;
/* These fields protected by kvm->lock */
+
+ /* Possible values and their usage:
+ * <0 an error occurred during allocation,
+ * -EBUSY allocation is in the progress,
+ * 0 allocation made successfuly.
+ */
int error;
- bool prepare_done;
- /* Private to the work thread, until prepare_done is true,
- * then protected by kvm->resize_hpt_sem */
+ /* Private to the work thread, until error != -EBUSY,
+ * then protected by kvm->lock.
+ */
struct kvm_hpt_info hpt;
};
@@ -159,8 +165,6 @@ long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
* Reset all the reverse-mapping chains for all memslots
*/
kvmppc_rmap_reset(kvm);
- /* Ensure that each vcpu will flush its TLB on next entry. */
- cpumask_setall(&kvm->arch.need_tlb_flush);
err = 0;
goto out;
}
@@ -176,6 +180,10 @@ long kvmppc_alloc_reset_hpt(struct kvm *kvm, int order)
kvmppc_set_hpt(kvm, &info);
out:
+ if (err == 0)
+ /* Ensure that each vcpu will flush its TLB on next entry. */
+ cpumask_setall(&kvm->arch.need_tlb_flush);
+
mutex_unlock(&kvm->lock);
return err;
}
@@ -1413,16 +1421,20 @@ static void resize_hpt_pivot(struct kvm_resize_hpt *resize)
static void resize_hpt_release(struct kvm *kvm, struct kvm_resize_hpt *resize)
{
- BUG_ON(kvm->arch.resize_hpt != resize);
+ if (WARN_ON(!mutex_is_locked(&kvm->lock)))
+ return;
if (!resize)
return;
- if (resize->hpt.virt)
- kvmppc_free_hpt(&resize->hpt);
+ if (resize->error != -EBUSY) {
+ if (resize->hpt.virt)
+ kvmppc_free_hpt(&resize->hpt);
+ kfree(resize);
+ }
- kvm->arch.resize_hpt = NULL;
- kfree(resize);
+ if (kvm->arch.resize_hpt == resize)
+ kvm->arch.resize_hpt = NULL;
}
static void resize_hpt_prepare_work(struct work_struct *work)
@@ -1431,17 +1443,41 @@ static void resize_hpt_prepare_work(struct work_struct *work)
struct kvm_resize_hpt,
work);
struct kvm *kvm = resize->kvm;
- int err;
+ int err = 0;
- resize_hpt_debug(resize, "resize_hpt_prepare_work(): order = %d\n",
- resize->order);
-
- err = resize_hpt_allocate(resize);
+ if (WARN_ON(resize->error != -EBUSY))
+ return;
mutex_lock(&kvm->lock);
+ /* Request is still current? */
+ if (kvm->arch.resize_hpt == resize) {
+ /* We may request large allocations here:
+ * do not sleep with kvm->lock held for a while.
+ */
+ mutex_unlock(&kvm->lock);
+
+ resize_hpt_debug(resize, "resize_hpt_prepare_work(): order = %d\n",
+ resize->order);
+
+ err = resize_hpt_allocate(resize);
+
+ /* We have strict assumption about -EBUSY
+ * when preparing for HPT resize.
+ */
+ if (WARN_ON(err == -EBUSY))
+ err = -EINPROGRESS;
+
+ mutex_lock(&kvm->lock);
+ /* It is possible that kvm->arch.resize_hpt != resize
+ * after we grab kvm->lock again.
+ */
+ }
+
resize->error = err;
- resize->prepare_done = true;
+
+ if (kvm->arch.resize_hpt != resize)
+ resize_hpt_release(kvm, resize);
mutex_unlock(&kvm->lock);
}
@@ -1466,14 +1502,12 @@ long kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm,
if (resize) {
if (resize->order == shift) {
- /* Suitable resize in progress */
- if (resize->prepare_done) {
- ret = resize->error;
- if (ret != 0)
- resize_hpt_release(kvm, resize);
- } else {
+ /* Suitable resize in progress? */
+ ret = resize->error;
+ if (ret == -EBUSY)
ret = 100; /* estimated time in ms */
- }
+ else if (ret)
+ resize_hpt_release(kvm, resize);
goto out;
}
@@ -1493,6 +1527,8 @@ long kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm,
ret = -ENOMEM;
goto out;
}
+
+ resize->error = -EBUSY;
resize->order = shift;
resize->kvm = kvm;
INIT_WORK(&resize->work, resize_hpt_prepare_work);
@@ -1547,16 +1583,12 @@ long kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm,
if (!resize || (resize->order != shift))
goto out;
- ret = -EBUSY;
- if (!resize->prepare_done)
- goto out;
-
ret = resize->error;
- if (ret != 0)
+ if (ret)
goto out;
ret = resize_hpt_rehash(resize);
- if (ret != 0)
+ if (ret)
goto out;
resize_hpt_pivot(resize);
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index d0dc8624198f..7deaeeb14b93 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -60,6 +60,7 @@ static void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac);
#define MSR_USER32 MSR_USER
#define MSR_USER64 MSR_USER
#define HW_PAGE_SIZE PAGE_SIZE
+#define HPTE_R_M _PAGE_COHERENT
#endif
static bool kvmppc_is_split_real(struct kvm_vcpu *vcpu)
@@ -557,6 +558,7 @@ int kvmppc_handle_pagefault(struct kvm_run *run, struct kvm_vcpu *vcpu,
pte.eaddr = eaddr;
pte.vpage = eaddr >> 12;
pte.page_size = MMU_PAGE_64K;
+ pte.wimg = HPTE_R_M;
}
switch (kvmppc_get_msr(vcpu) & (MSR_DR|MSR_IR)) {
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index c4deb1f34faa..2b8eb4da4d08 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3781,7 +3781,8 @@ static int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn)
bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu)
{
if (unlikely(!lapic_in_kernel(vcpu) ||
- kvm_event_needs_reinjection(vcpu)))
+ kvm_event_needs_reinjection(vcpu) ||
+ vcpu->arch.exception.pending))
return false;
if (!vcpu->arch.apf.delivery_as_pf_vmexit && is_guest_mode(vcpu))
@@ -5465,30 +5466,34 @@ static void mmu_destroy_caches(void)
int kvm_mmu_module_init(void)
{
+ int ret = -ENOMEM;
+
kvm_mmu_clear_all_pte_masks();
pte_list_desc_cache = kmem_cache_create("pte_list_desc",
sizeof(struct pte_list_desc),
0, SLAB_ACCOUNT, NULL);
if (!pte_list_desc_cache)
- goto nomem;
+ goto out;
mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
sizeof(struct kvm_mmu_page),
0, SLAB_ACCOUNT, NULL);
if (!mmu_page_header_cache)
- goto nomem;
+ goto out;
if (percpu_counter_init(&kvm_total_used_mmu_pages, 0, GFP_KERNEL))
- goto nomem;
+ goto out;
- register_shrinker(&mmu_shrinker);
+ ret = register_shrinker(&mmu_shrinker);
+ if (ret)
+ goto out;
return 0;
-nomem:
+out:
mmu_destroy_caches();
- return -ENOMEM;
+ return ret;
}
/*
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index bb31c801f1fc..3158dac87f82 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -361,7 +361,6 @@ static void recalc_intercepts(struct vcpu_svm *svm)
{
struct vmcb_control_area *c, *h;
struct nested_state *g;
- u32 h_intercept_exceptions;
mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
@@ -372,14 +371,9 @@ static void recalc_intercepts(struct vcpu_svm *svm)
h = &svm->nested.hsave->control;
g = &svm->nested;
- /* No need to intercept #UD if L1 doesn't intercept it */
- h_intercept_exceptions =
- h->intercept_exceptions & ~(1U << UD_VECTOR);
-
c->intercept_cr = h->intercept_cr | g->intercept_cr;
c->intercept_dr = h->intercept_dr | g->intercept_dr;
- c->intercept_exceptions =
- h_intercept_exceptions | g->intercept_exceptions;
+ c->intercept_exceptions = h->intercept_exceptions | g->intercept_exceptions;
c->intercept = h->intercept | g->intercept;
}
@@ -2202,7 +2196,6 @@ static int ud_interception(struct vcpu_svm *svm)
{
int er;
- WARN_ON_ONCE(is_guest_mode(&svm->vcpu));
er = emulate_instruction(&svm->vcpu, EMULTYPE_TRAP_UD);
if (er == EMULATE_USER_EXIT)
return 0;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 5c14d65f676a..3f89f6783aa5 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -899,8 +899,16 @@ static inline short vmcs_field_to_offset(unsigned long field)
{
BUILD_BUG_ON(ARRAY_SIZE(vmcs_field_to_offset_table) > SHRT_MAX);
- if (field >= ARRAY_SIZE(vmcs_field_to_offset_table) ||
- vmcs_field_to_offset_table[field] == 0)
+ if (field >= ARRAY_SIZE(vmcs_field_to_offset_table))
+ return -ENOENT;
+
+ /*
+ * FIXME: Mitigation for CVE-2017-5753. To be replaced with a
+ * generic mechanism.
+ */
+ asm("lfence");
+
+ if (vmcs_field_to_offset_table[field] == 0)
return -ENOENT;
return vmcs_field_to_offset_table[field];
@@ -1887,7 +1895,7 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu)
{
u32 eb;
- eb = (1u << PF_VECTOR) | (1u << MC_VECTOR) |
+ eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) |
(1u << DB_VECTOR) | (1u << AC_VECTOR);
if ((vcpu->guest_debug &
(KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)) ==
@@ -1905,8 +1913,6 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu)
*/
if (is_guest_mode(vcpu))
eb |= get_vmcs12(vcpu)->exception_bitmap;
- else
- eb |= 1u << UD_VECTOR;
vmcs_write32(EXCEPTION_BITMAP, eb);
}
@@ -5917,7 +5923,6 @@ static int handle_exception(struct kvm_vcpu *vcpu)
return 1; /* already handled by vmx_vcpu_run() */
if (is_invalid_opcode(intr_info)) {
- WARN_ON_ONCE(is_guest_mode(vcpu));
er = emulate_instruction(vcpu, EMULTYPE_TRAP_UD);
if (er == EMULATE_USER_EXIT)
return 0;

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