5.4-stable patches

added patches:
	dm-fix-bio-splitting-and-its-bio-completion-order-for-regular-io.patch
	kvm-arm64-assume-write-fault-on-s1ptw-permission-fault-on-instruction-fetch.patch

diff --git a/queue-5.4/dm-fix-bio-splitting-and-its-bio-completion-order-for-regular-io.patch b/queue-5.4/dm-fix-bio-splitting-and-its-bio-completion-order-for-regular-io.patch
new file mode 100644 (file)
index 0000000..61f299d
--- /dev/null
+++ b/queue-5.4/dm-fix-bio-splitting-and-its-bio-completion-order-for-regular-io.patch
@@ -0,0 +1,75 @@
+From ee1dfad5325ff1cfb2239e564cd411b3bfe8667a Mon Sep 17 00:00:00 2001
+From: Mike Snitzer <snitzer@redhat.com>
+Date: Mon, 14 Sep 2020 13:04:19 -0400
+Subject: dm: fix bio splitting and its bio completion order for regular IO
+
+From: Mike Snitzer <snitzer@redhat.com>
+
+commit ee1dfad5325ff1cfb2239e564cd411b3bfe8667a upstream.
+
+dm_queue_split() is removed because __split_and_process_bio() _must_
+handle splitting bios to ensure proper bio submission and completion
+ordering as a bio is split.
+
+Otherwise, multiple recursive calls to ->submit_bio will cause multiple
+split bios to be allocated from the same ->bio_split mempool at the same
+time. This would result in deadlock in low memory conditions because no
+progress could be made (only one bio is available in ->bio_split
+mempool).
+
+This fix has been verified to still fix the loss of performance, due
+to excess splitting, that commit 120c9257f5f1 provided.
+
+Fixes: 120c9257f5f1 ("Revert "dm: always call blk_queue_split() in dm_process_bio()"")
+Cc: stable@vger.kernel.org # 5.0+, requires custom backport due to 5.9 changes
+Reported-by: Ming Lei <ming.lei@redhat.com>
+Signed-off-by: Mike Snitzer <snitzer@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/md/dm.c |   23 ++---------------------
+ 1 file changed, 2 insertions(+), 21 deletions(-)
+
+--- a/drivers/md/dm.c
++++ b/drivers/md/dm.c
+@@ -1720,23 +1720,6 @@ out:
+       return ret;
+ }
+ 
+-static void dm_queue_split(struct mapped_device *md, struct dm_target *ti, struct bio **bio)
+-{
+-      unsigned len, sector_count;
+-
+-      sector_count = bio_sectors(*bio);
+-      len = min_t(sector_t, max_io_len((*bio)->bi_iter.bi_sector, ti), sector_count);
+-
+-      if (sector_count > len) {
+-              struct bio *split = bio_split(*bio, len, GFP_NOIO, &md->queue->bio_split);
+-
+-              bio_chain(split, *bio);
+-              trace_block_split(md->queue, split, (*bio)->bi_iter.bi_sector);
+-              generic_make_request(*bio);
+-              *bio = split;
+-      }
+-}
+-
+ static blk_qc_t dm_process_bio(struct mapped_device *md,
+                              struct dm_table *map, struct bio *bio)
+ {
+@@ -1764,14 +1747,12 @@ static blk_qc_t dm_process_bio(struct ma
+       if (current->bio_list) {
+               if (is_abnormal_io(bio))
+                       blk_queue_split(md->queue, &bio);
+-              else
+-                      dm_queue_split(md, ti, &bio);
++              /* regular IO is split by __split_and_process_bio */
+       }
+ 
+       if (dm_get_md_type(md) == DM_TYPE_NVME_BIO_BASED)
+               return __process_bio(md, map, bio, ti);
+-      else
+-              return __split_and_process_bio(md, map, bio);
++      return __split_and_process_bio(md, map, bio);
+ }
+ 
+ static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio)

diff --git a/queue-5.4/kvm-arm64-assume-write-fault-on-s1ptw-permission-fault-on-instruction-fetch.patch b/queue-5.4/kvm-arm64-assume-write-fault-on-s1ptw-permission-fault-on-instruction-fetch.patch
new file mode 100644 (file)
index 0000000..ed5aa2a
--- /dev/null
+++ b/queue-5.4/kvm-arm64-assume-write-fault-on-s1ptw-permission-fault-on-instruction-fetch.patch
@@ -0,0 +1,154 @@
+From c4ad98e4b72cb5be30ea282fce935248f2300e62 Mon Sep 17 00:00:00 2001
+From: Marc Zyngier <maz@kernel.org>
+Date: Tue, 15 Sep 2020 11:42:17 +0100
+Subject: KVM: arm64: Assume write fault on S1PTW permission fault on instruction fetch
+
+From: Marc Zyngier <maz@kernel.org>
+
+commit c4ad98e4b72cb5be30ea282fce935248f2300e62 upstream.
+
+KVM currently assumes that an instruction abort can never be a write.
+This is in general true, except when the abort is triggered by
+a S1PTW on instruction fetch that tries to update the S1 page tables
+(to set AF, for example).
+
+This can happen if the page tables have been paged out and brought
+back in without seeing a direct write to them (they are thus marked
+read only), and the fault handling code will make the PT executable(!)
+instead of writable. The guest gets stuck forever.
+
+In these conditions, the permission fault must be considered as
+a write so that the Stage-1 update can take place. This is essentially
+the I-side equivalent of the problem fixed by 60e21a0ef54c ("arm64: KVM:
+Take S1 walks into account when determining S2 write faults").
+
+Update kvm_is_write_fault() to return true on IABT+S1PTW, and introduce
+kvm_vcpu_trap_is_exec_fault() that only return true when no faulting
+on a S1 fault. Additionally, kvm_vcpu_dabt_iss1tw() is renamed to
+kvm_vcpu_abt_iss1tw(), as the above makes it plain that it isn't
+specific to data abort.
+
+Signed-off-by: Marc Zyngier <maz@kernel.org>
+Reviewed-by: Will Deacon <will@kernel.org>
+Cc: stable@vger.kernel.org
+Link: https://lore.kernel.org/r/20200915104218.1284701-2-maz@kernel.org
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/arm/include/asm/kvm_emulate.h   |   11 ++++++++---
+ arch/arm64/include/asm/kvm_emulate.h |   12 ++++++++++--
+ arch/arm64/kvm/hyp/switch.c          |    2 +-
+ virt/kvm/arm/mmio.c                  |    2 +-
+ virt/kvm/arm/mmu.c                   |    2 +-
+ 5 files changed, 21 insertions(+), 8 deletions(-)
+
+--- a/arch/arm/include/asm/kvm_emulate.h
++++ b/arch/arm/include/asm/kvm_emulate.h
+@@ -204,7 +204,7 @@ static inline int kvm_vcpu_dabt_get_rd(s
+       return (kvm_vcpu_get_hsr(vcpu) & HSR_SRT_MASK) >> HSR_SRT_SHIFT;
+ }
+ 
+-static inline bool kvm_vcpu_dabt_iss1tw(struct kvm_vcpu *vcpu)
++static inline bool kvm_vcpu_abt_iss1tw(const struct kvm_vcpu *vcpu)
+ {
+       return kvm_vcpu_get_hsr(vcpu) & HSR_DABT_S1PTW;
+ }
+@@ -236,16 +236,21 @@ static inline bool kvm_vcpu_trap_il_is32
+       return kvm_vcpu_get_hsr(vcpu) & HSR_IL;
+ }
+ 
+-static inline u8 kvm_vcpu_trap_get_class(struct kvm_vcpu *vcpu)
++static inline u8 kvm_vcpu_trap_get_class(const struct kvm_vcpu *vcpu)
+ {
+       return kvm_vcpu_get_hsr(vcpu) >> HSR_EC_SHIFT;
+ }
+ 
+-static inline bool kvm_vcpu_trap_is_iabt(struct kvm_vcpu *vcpu)
++static inline bool kvm_vcpu_trap_is_iabt(const struct kvm_vcpu *vcpu)
+ {
+       return kvm_vcpu_trap_get_class(vcpu) == HSR_EC_IABT;
+ }
+ 
++static inline bool kvm_vcpu_trap_is_exec_fault(const struct kvm_vcpu *vcpu)
++{
++      return kvm_vcpu_trap_is_iabt(vcpu) && !kvm_vcpu_abt_iss1tw(vcpu);
++}
++
+ static inline u8 kvm_vcpu_trap_get_fault(struct kvm_vcpu *vcpu)
+ {
+       return kvm_vcpu_get_hsr(vcpu) & HSR_FSC;
+--- a/arch/arm64/include/asm/kvm_emulate.h
++++ b/arch/arm64/include/asm/kvm_emulate.h
+@@ -299,7 +299,7 @@ static inline int kvm_vcpu_dabt_get_rd(c
+       return (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT;
+ }
+ 
+-static inline bool kvm_vcpu_dabt_iss1tw(const struct kvm_vcpu *vcpu)
++static __always_inline bool kvm_vcpu_abt_iss1tw(const struct kvm_vcpu *vcpu)
+ {
+       return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_S1PTW);
+ }
+@@ -307,7 +307,7 @@ static inline bool kvm_vcpu_dabt_iss1tw(
+ static inline bool kvm_vcpu_dabt_iswrite(const struct kvm_vcpu *vcpu)
+ {
+       return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WNR) ||
+-              kvm_vcpu_dabt_iss1tw(vcpu); /* AF/DBM update */
++              kvm_vcpu_abt_iss1tw(vcpu); /* AF/DBM update */
+ }
+ 
+ static inline bool kvm_vcpu_dabt_is_cm(const struct kvm_vcpu *vcpu)
+@@ -336,6 +336,11 @@ static inline bool kvm_vcpu_trap_is_iabt
+       return kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_IABT_LOW;
+ }
+ 
++static inline bool kvm_vcpu_trap_is_exec_fault(const struct kvm_vcpu *vcpu)
++{
++      return kvm_vcpu_trap_is_iabt(vcpu) && !kvm_vcpu_abt_iss1tw(vcpu);
++}
++
+ static inline u8 kvm_vcpu_trap_get_fault(const struct kvm_vcpu *vcpu)
+ {
+       return kvm_vcpu_get_hsr(vcpu) & ESR_ELx_FSC;
+@@ -373,6 +378,9 @@ static inline int kvm_vcpu_sys_get_rt(st
+ 
+ static inline bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
+ {
++      if (kvm_vcpu_abt_iss1tw(vcpu))
++              return true;
++
+       if (kvm_vcpu_trap_is_iabt(vcpu))
+               return false;
+ 
+--- a/arch/arm64/kvm/hyp/switch.c
++++ b/arch/arm64/kvm/hyp/switch.c
+@@ -496,7 +496,7 @@ static bool __hyp_text fixup_guest_exit(
+                       kvm_vcpu_trap_get_fault_type(vcpu) == FSC_FAULT &&
+                       kvm_vcpu_dabt_isvalid(vcpu) &&
+                       !kvm_vcpu_dabt_isextabt(vcpu) &&
+-                      !kvm_vcpu_dabt_iss1tw(vcpu);
++                      !kvm_vcpu_abt_iss1tw(vcpu);
+ 
+               if (valid) {
+                       int ret = __vgic_v2_perform_cpuif_access(vcpu);
+--- a/virt/kvm/arm/mmio.c
++++ b/virt/kvm/arm/mmio.c
+@@ -130,7 +130,7 @@ static int decode_hsr(struct kvm_vcpu *v
+       bool sign_extend;
+       bool sixty_four;
+ 
+-      if (kvm_vcpu_dabt_iss1tw(vcpu)) {
++      if (kvm_vcpu_abt_iss1tw(vcpu)) {
+               /* page table accesses IO mem: tell guest to fix its TTBR */
+               kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
+               return 1;
+--- a/virt/kvm/arm/mmu.c
++++ b/virt/kvm/arm/mmu.c
+@@ -1690,7 +1690,7 @@ static int user_mem_abort(struct kvm_vcp
+       unsigned long vma_pagesize, flags = 0;
+ 
+       write_fault = kvm_is_write_fault(vcpu);
+-      exec_fault = kvm_vcpu_trap_is_iabt(vcpu);
++      exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu);
+       VM_BUG_ON(write_fault && exec_fault);
+ 
+       if (fault_status == FSC_PERM && !write_fault && !exec_fault) {

diff --git a/queue-5.4/series b/queue-5.4/series
index 874e3a29433b585ad6b3afb98b52d885263a53b0..9dcf98e6d9b981fdcbe5dfa7a30b293e1d043f9c 100644 (file)
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -383,3 +383,5 @@ dmabuf-fix-null-pointer-dereference-in-dma_buf_release.patch
 mm-thp-swap-fix-allocating-cluster-for-swapfile-by-mistake.patch
 mm-gup-fix-gup_fast-with-dynamic-page-table-folding.patch
 s390-zcrypt-fix-zcrypt_perdev_reqcnt-ioctl.patch
+kvm-arm64-assume-write-fault-on-s1ptw-permission-fault-on-instruction-fetch.patch
+dm-fix-bio-splitting-and-its-bio-completion-order-for-regular-io.patch