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authorPaolo Bonzini <pbonzini@redhat.com>2019-03-28 19:07:30 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2019-03-28 19:07:30 +0100
commit690edec54cbaa0e98dc592aae6864272f48f3c84 (patch)
treeb2240e1aa7f39f65d042e0d1dee94df6b67d4a60 /virt
parente2788c4a41cb5fa68096f5a58bccacec1a700295 (diff)
parent8324c3d518cfd69f2a17866b52c13bf56d3042d8 (diff)
downloadlinux-stericsson-690edec54cbaa0e98dc592aae6864272f48f3c84.tar.gz
Merge tag 'kvmarm-fixes-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master
KVM/ARM fixes for 5.1 - Fix THP handling in the presence of pre-existing PTEs - Honor request for PTE mappings even when THPs are available - GICv4 performance improvement - Take the srcu lock when writing to guest-controlled ITS data structures - Reset the virtual PMU in preemptible context - Various cleanups
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/arm/hyp/vgic-v3-sr.c4
-rw-r--r--virt/kvm/arm/mmu.c125
-rw-r--r--virt/kvm/arm/vgic/vgic-its.c31
-rw-r--r--virt/kvm/arm/vgic/vgic-v3.c4
-rw-r--r--virt/kvm/arm/vgic/vgic.c14
5 files changed, 106 insertions, 72 deletions
diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
index 264d92da3240..370bd6c5e6cb 100644
--- a/virt/kvm/arm/hyp/vgic-v3-sr.c
+++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
@@ -222,7 +222,7 @@ void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
}
}
- if (used_lrs) {
+ if (used_lrs || cpu_if->its_vpe.its_vm) {
int i;
u32 elrsr;
@@ -247,7 +247,7 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
int i;
- if (used_lrs) {
+ if (used_lrs || cpu_if->its_vpe.its_vm) {
write_gicreg(cpu_if->vgic_hcr, ICH_HCR_EL2);
for (i = 0; i < used_lrs; i++)
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index ffd7acdceac7..27c958306449 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -102,8 +102,7 @@ static bool kvm_is_device_pfn(unsigned long pfn)
* @addr: IPA
* @pmd: pmd pointer for IPA
*
- * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. Marks all
- * pages in the range dirty.
+ * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs.
*/
static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd)
{
@@ -121,8 +120,7 @@ static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd)
* @addr: IPA
* @pud: pud pointer for IPA
*
- * Function clears a PUD entry, flushes addr 1st and 2nd stage TLBs. Marks all
- * pages in the range dirty.
+ * Function clears a PUD entry, flushes addr 1st and 2nd stage TLBs.
*/
static void stage2_dissolve_pud(struct kvm *kvm, phys_addr_t addr, pud_t *pudp)
{
@@ -899,9 +897,8 @@ int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size,
* kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
* @kvm: The KVM struct pointer for the VM.
*
- * Allocates only the stage-2 HW PGD level table(s) (can support either full
- * 40-bit input addresses or limited to 32-bit input addresses). Clears the
- * allocated pages.
+ * Allocates only the stage-2 HW PGD level table(s) of size defined by
+ * stage2_pgd_size(kvm).
*
* Note we don't need locking here as this is only called when the VM is
* created, which can only be done once.
@@ -1067,25 +1064,43 @@ static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache
{
pmd_t *pmd, old_pmd;
+retry:
pmd = stage2_get_pmd(kvm, cache, addr);
VM_BUG_ON(!pmd);
old_pmd = *pmd;
+ /*
+ * Multiple vcpus faulting on the same PMD entry, can
+ * lead to them sequentially updating the PMD with the
+ * same value. Following the break-before-make
+ * (pmd_clear() followed by tlb_flush()) process can
+ * hinder forward progress due to refaults generated
+ * on missing translations.
+ *
+ * Skip updating the page table if the entry is
+ * unchanged.
+ */
+ if (pmd_val(old_pmd) == pmd_val(*new_pmd))
+ return 0;
+
if (pmd_present(old_pmd)) {
/*
- * Multiple vcpus faulting on the same PMD entry, can
- * lead to them sequentially updating the PMD with the
- * same value. Following the break-before-make
- * (pmd_clear() followed by tlb_flush()) process can
- * hinder forward progress due to refaults generated
- * on missing translations.
+ * If we already have PTE level mapping for this block,
+ * we must unmap it to avoid inconsistent TLB state and
+ * leaking the table page. We could end up in this situation
+ * if the memory slot was marked for dirty logging and was
+ * reverted, leaving PTE level mappings for the pages accessed
+ * during the period. So, unmap the PTE level mapping for this
+ * block and retry, as we could have released the upper level
+ * table in the process.
*
- * Skip updating the page table if the entry is
- * unchanged.
+ * Normal THP split/merge follows mmu_notifier callbacks and do
+ * get handled accordingly.
*/
- if (pmd_val(old_pmd) == pmd_val(*new_pmd))
- return 0;
-
+ if (!pmd_thp_or_huge(old_pmd)) {
+ unmap_stage2_range(kvm, addr & S2_PMD_MASK, S2_PMD_SIZE);
+ goto retry;
+ }
/*
* Mapping in huge pages should only happen through a
* fault. If a page is merged into a transparent huge
@@ -1097,8 +1112,7 @@ static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache
* should become splitting first, unmapped, merged,
* and mapped back in on-demand.
*/
- VM_BUG_ON(pmd_pfn(old_pmd) != pmd_pfn(*new_pmd));
-
+ WARN_ON_ONCE(pmd_pfn(old_pmd) != pmd_pfn(*new_pmd));
pmd_clear(pmd);
kvm_tlb_flush_vmid_ipa(kvm, addr);
} else {
@@ -1114,6 +1128,7 @@ static int stage2_set_pud_huge(struct kvm *kvm, struct kvm_mmu_memory_cache *cac
{
pud_t *pudp, old_pud;
+retry:
pudp = stage2_get_pud(kvm, cache, addr);
VM_BUG_ON(!pudp);
@@ -1121,14 +1136,23 @@ static int stage2_set_pud_huge(struct kvm *kvm, struct kvm_mmu_memory_cache *cac
/*
* A large number of vcpus faulting on the same stage 2 entry,
- * can lead to a refault due to the
- * stage2_pud_clear()/tlb_flush(). Skip updating the page
- * tables if there is no change.
+ * can lead to a refault due to the stage2_pud_clear()/tlb_flush().
+ * Skip updating the page tables if there is no change.
*/
if (pud_val(old_pud) == pud_val(*new_pudp))
return 0;
if (stage2_pud_present(kvm, old_pud)) {
+ /*
+ * If we already have table level mapping for this block, unmap
+ * the range for this block and retry.
+ */
+ if (!stage2_pud_huge(kvm, old_pud)) {
+ unmap_stage2_range(kvm, addr & S2_PUD_MASK, S2_PUD_SIZE);
+ goto retry;
+ }
+
+ WARN_ON_ONCE(kvm_pud_pfn(old_pud) != kvm_pud_pfn(*new_pudp));
stage2_pud_clear(kvm, pudp);
kvm_tlb_flush_vmid_ipa(kvm, addr);
} else {
@@ -1451,13 +1475,11 @@ static void stage2_wp_pmds(struct kvm *kvm, pud_t *pud,
}
/**
- * stage2_wp_puds - write protect PGD range
- * @pgd: pointer to pgd entry
- * @addr: range start address
- * @end: range end address
- *
- * Process PUD entries, for a huge PUD we cause a panic.
- */
+ * stage2_wp_puds - write protect PGD range
+ * @pgd: pointer to pgd entry
+ * @addr: range start address
+ * @end: range end address
+ */
static void stage2_wp_puds(struct kvm *kvm, pgd_t *pgd,
phys_addr_t addr, phys_addr_t end)
{
@@ -1594,8 +1616,9 @@ static void kvm_send_hwpoison_signal(unsigned long address,
send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb, current);
}
-static bool fault_supports_stage2_pmd_mappings(struct kvm_memory_slot *memslot,
- unsigned long hva)
+static bool fault_supports_stage2_huge_mapping(struct kvm_memory_slot *memslot,
+ unsigned long hva,
+ unsigned long map_size)
{
gpa_t gpa_start;
hva_t uaddr_start, uaddr_end;
@@ -1610,34 +1633,34 @@ static bool fault_supports_stage2_pmd_mappings(struct kvm_memory_slot *memslot,
/*
* Pages belonging to memslots that don't have the same alignment
- * within a PMD for userspace and IPA cannot be mapped with stage-2
- * PMD entries, because we'll end up mapping the wrong pages.
+ * within a PMD/PUD for userspace and IPA cannot be mapped with stage-2
+ * PMD/PUD entries, because we'll end up mapping the wrong pages.
*
* Consider a layout like the following:
*
* memslot->userspace_addr:
* +-----+--------------------+--------------------+---+
- * |abcde|fgh Stage-1 PMD | Stage-1 PMD tv|xyz|
+ * |abcde|fgh Stage-1 block | Stage-1 block tv|xyz|
* +-----+--------------------+--------------------+---+
*
* memslot->base_gfn << PAGE_SIZE:
* +---+--------------------+--------------------+-----+
- * |abc|def Stage-2 PMD | Stage-2 PMD |tvxyz|
+ * |abc|def Stage-2 block | Stage-2 block |tvxyz|
* +---+--------------------+--------------------+-----+
*
- * If we create those stage-2 PMDs, we'll end up with this incorrect
+ * If we create those stage-2 blocks, we'll end up with this incorrect
* mapping:
* d -> f
* e -> g
* f -> h
*/
- if ((gpa_start & ~S2_PMD_MASK) != (uaddr_start & ~S2_PMD_MASK))
+ if ((gpa_start & (map_size - 1)) != (uaddr_start & (map_size - 1)))
return false;
/*
* Next, let's make sure we're not trying to map anything not covered
- * by the memslot. This means we have to prohibit PMD size mappings
- * for the beginning and end of a non-PMD aligned and non-PMD sized
+ * by the memslot. This means we have to prohibit block size mappings
+ * for the beginning and end of a non-block aligned and non-block sized
* memory slot (illustrated by the head and tail parts of the
* userspace view above containing pages 'abcde' and 'xyz',
* respectively).
@@ -1646,8 +1669,8 @@ static bool fault_supports_stage2_pmd_mappings(struct kvm_memory_slot *memslot,
* userspace_addr or the base_gfn, as both are equally aligned (per
* the check above) and equally sized.
*/
- return (hva & S2_PMD_MASK) >= uaddr_start &&
- (hva & S2_PMD_MASK) + S2_PMD_SIZE <= uaddr_end;
+ return (hva & ~(map_size - 1)) >= uaddr_start &&
+ (hva & ~(map_size - 1)) + map_size <= uaddr_end;
}
static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
@@ -1676,12 +1699,6 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
return -EFAULT;
}
- if (!fault_supports_stage2_pmd_mappings(memslot, hva))
- force_pte = true;
-
- if (logging_active)
- force_pte = true;
-
/* Let's check if we will get back a huge page backed by hugetlbfs */
down_read(&current->mm->mmap_sem);
vma = find_vma_intersection(current->mm, hva, hva + 1);
@@ -1692,6 +1709,12 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
}
vma_pagesize = vma_kernel_pagesize(vma);
+ if (logging_active ||
+ !fault_supports_stage2_huge_mapping(memslot, hva, vma_pagesize)) {
+ force_pte = true;
+ vma_pagesize = PAGE_SIZE;
+ }
+
/*
* The stage2 has a minimum of 2 level table (For arm64 see
* kvm_arm_setup_stage2()). Hence, we are guaranteed that we can
@@ -1699,11 +1722,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
* As for PUD huge maps, we must make sure that we have at least
* 3 levels, i.e, PMD is not folded.
*/
- if ((vma_pagesize == PMD_SIZE ||
- (vma_pagesize == PUD_SIZE && kvm_stage2_has_pmd(kvm))) &&
- !force_pte) {
+ if (vma_pagesize == PMD_SIZE ||
+ (vma_pagesize == PUD_SIZE && kvm_stage2_has_pmd(kvm)))
gfn = (fault_ipa & huge_page_mask(hstate_vma(vma))) >> PAGE_SHIFT;
- }
up_read(&current->mm->mmap_sem);
/* We need minimum second+third level pages */
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index ab3f47745d9c..44ceaccb18cf 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -754,8 +754,9 @@ static bool vgic_its_check_id(struct vgic_its *its, u64 baser, u32 id,
u64 indirect_ptr, type = GITS_BASER_TYPE(baser);
phys_addr_t base = GITS_BASER_ADDR_48_to_52(baser);
int esz = GITS_BASER_ENTRY_SIZE(baser);
- int index;
+ int index, idx;
gfn_t gfn;
+ bool ret;
switch (type) {
case GITS_BASER_TYPE_DEVICE:
@@ -782,7 +783,8 @@ static bool vgic_its_check_id(struct vgic_its *its, u64 baser, u32 id,
if (eaddr)
*eaddr = addr;
- return kvm_is_visible_gfn(its->dev->kvm, gfn);
+
+ goto out;
}
/* calculate and check the index into the 1st level */
@@ -812,7 +814,12 @@ static bool vgic_its_check_id(struct vgic_its *its, u64 baser, u32 id,
if (eaddr)
*eaddr = indirect_ptr;
- return kvm_is_visible_gfn(its->dev->kvm, gfn);
+
+out:
+ idx = srcu_read_lock(&its->dev->kvm->srcu);
+ ret = kvm_is_visible_gfn(its->dev->kvm, gfn);
+ srcu_read_unlock(&its->dev->kvm->srcu, idx);
+ return ret;
}
static int vgic_its_alloc_collection(struct vgic_its *its,
@@ -1729,8 +1736,8 @@ static void vgic_its_destroy(struct kvm_device *kvm_dev)
kfree(its);
}
-int vgic_its_has_attr_regs(struct kvm_device *dev,
- struct kvm_device_attr *attr)
+static int vgic_its_has_attr_regs(struct kvm_device *dev,
+ struct kvm_device_attr *attr)
{
const struct vgic_register_region *region;
gpa_t offset = attr->attr;
@@ -1750,9 +1757,9 @@ int vgic_its_has_attr_regs(struct kvm_device *dev,
return 0;
}
-int vgic_its_attr_regs_access(struct kvm_device *dev,
- struct kvm_device_attr *attr,
- u64 *reg, bool is_write)
+static int vgic_its_attr_regs_access(struct kvm_device *dev,
+ struct kvm_device_attr *attr,
+ u64 *reg, bool is_write)
{
const struct vgic_register_region *region;
struct vgic_its *its;
@@ -1919,7 +1926,7 @@ static int vgic_its_save_ite(struct vgic_its *its, struct its_device *dev,
((u64)ite->irq->intid << KVM_ITS_ITE_PINTID_SHIFT) |
ite->collection->collection_id;
val = cpu_to_le64(val);
- return kvm_write_guest(kvm, gpa, &val, ite_esz);
+ return kvm_write_guest_lock(kvm, gpa, &val, ite_esz);
}
/**
@@ -2066,7 +2073,7 @@ static int vgic_its_save_dte(struct vgic_its *its, struct its_device *dev,
(itt_addr_field << KVM_ITS_DTE_ITTADDR_SHIFT) |
(dev->num_eventid_bits - 1));
val = cpu_to_le64(val);
- return kvm_write_guest(kvm, ptr, &val, dte_esz);
+ return kvm_write_guest_lock(kvm, ptr, &val, dte_esz);
}
/**
@@ -2246,7 +2253,7 @@ static int vgic_its_save_cte(struct vgic_its *its,
((u64)collection->target_addr << KVM_ITS_CTE_RDBASE_SHIFT) |
collection->collection_id);
val = cpu_to_le64(val);
- return kvm_write_guest(its->dev->kvm, gpa, &val, esz);
+ return kvm_write_guest_lock(its->dev->kvm, gpa, &val, esz);
}
static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz)
@@ -2317,7 +2324,7 @@ static int vgic_its_save_collection_table(struct vgic_its *its)
*/
val = 0;
BUG_ON(cte_esz > sizeof(val));
- ret = kvm_write_guest(its->dev->kvm, gpa, &val, cte_esz);
+ ret = kvm_write_guest_lock(its->dev->kvm, gpa, &val, cte_esz);
return ret;
}
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 408a78eb6a97..9f87e58dbd4a 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -358,7 +358,7 @@ retry:
if (status) {
/* clear consumed data */
val &= ~(1 << bit_nr);
- ret = kvm_write_guest(kvm, ptr, &val, 1);
+ ret = kvm_write_guest_lock(kvm, ptr, &val, 1);
if (ret)
return ret;
}
@@ -409,7 +409,7 @@ int vgic_v3_save_pending_tables(struct kvm *kvm)
else
val &= ~(1 << bit_nr);
- ret = kvm_write_guest(kvm, ptr, &val, 1);
+ ret = kvm_write_guest_lock(kvm, ptr, &val, 1);
if (ret)
return ret;
}
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index abd9c7352677..3af69f2a3866 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -867,15 +867,21 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
* either observe the new interrupt before or after doing this check,
* and introducing additional synchronization mechanism doesn't change
* this.
+ *
+ * Note that we still need to go through the whole thing if anything
+ * can be directly injected (GICv4).
*/
- if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
+ if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head) &&
+ !vgic_supports_direct_msis(vcpu->kvm))
return;
DEBUG_SPINLOCK_BUG_ON(!irqs_disabled());
- raw_spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock);
- vgic_flush_lr_state(vcpu);
- raw_spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
+ if (!list_empty(&vcpu->arch.vgic_cpu.ap_list_head)) {
+ raw_spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock);
+ vgic_flush_lr_state(vcpu);
+ raw_spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
+ }
if (can_access_vgic_from_kernel())
vgic_restore_state(vcpu);