* Mon Jan 17 2022 Miroslav Rezanina <mrezanin@redhat.com> - 6.2.0-4

- kvm-block-nvme-fix-infinite-loop-in-nvme_free_req_queue_.patch [bz#2024544] - kvm-rhel-machine-types-x86-set-prefer_sockets.patch [bz#2028623] - Resolves: bz#2024544 (Fio workers hangs when running fio with 32 jobs iodepth 32 and QEMU's userspace NVMe driver) - Resolves: bz#2028623 ([9.0] machine types: 6.2: Fix prefer_sockets)
2022-01-17 06:13:57 -05:00 · 2022-01-17 06:13:57 -05:00 · 365a1410b6
commit 365a1410b6
parent e9000b6628
3 changed files with 138 additions and 1 deletions
--- a/kvm-block-nvme-fix-infinite-loop-in-nvme_free_req_queue_.patch
+++ b/kvm-block-nvme-fix-infinite-loop-in-nvme_free_req_queue_.patch
@ -0,0 +1,71 @@
+From 6989be9d0aa08470f8b287c243dc4bf027d5fbcf Mon Sep 17 00:00:00 2001
+From: Stefan Hajnoczi <stefanha@redhat.com>
+Date: Wed, 8 Dec 2021 15:22:46 +0000
+Subject: [PATCH 1/2] block/nvme: fix infinite loop in nvme_free_req_queue_cb()
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+RH-Author: Stefan Hajnoczi <stefanha@redhat.com>
+RH-MergeRequest: 58: block/nvme: fix infinite loop in nvme_free_req_queue_cb()
+RH-Commit: [1/1] 544b3f310d791a20c63b51947de0c6cbb60b0d5b (stefanha/centos-stream-qemu-kvm)
+RH-Bugzilla: 2024544
+RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
+RH-Acked-by: Stefano Garzarella <sgarzare@redhat.com>
+RH-Acked-by: Hanna Reitz <hreitz@redhat.com>
+
+When the request free list is exhausted the coroutine waits on
+q->free_req_queue for the next free request. Whenever a request is
+completed a BH is scheduled to invoke nvme_free_req_queue_cb() and wake
+up waiting coroutines.
+
+1. nvme_get_free_req() waits for a free request:
+
+    while (q->free_req_head == -1) {
+        ...
+            trace_nvme_free_req_queue_wait(q->s, q->index);
+            qemu_co_queue_wait(&q->free_req_queue, &q->lock);
+        ...
+    }
+
+2. nvme_free_req_queue_cb() wakes up the coroutine:
+
+    while (qemu_co_enter_next(&q->free_req_queue, &q->lock)) {
+       ^--- infinite loop when free_req_head == -1
+    }
+
+nvme_free_req_queue_cb() and the coroutine form an infinite loop when
+q->free_req_head == -1. Fix this by checking q->free_req_head in
+nvme_free_req_queue_cb(). If the free request list is exhausted, don't
+wake waiting coroutines. Eventually an in-flight request will complete
+and the BH will be scheduled again, guaranteeing forward progress.
+
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
+Message-id: 20211208152246.244585-1-stefanha@redhat.com
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+(cherry picked from commit cf4fbc3030c974fff726756a7ceef8386cdf500b)
+Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
+---
+ block/nvme.c | 5 +++--
+ 1 file changed, 3 insertions(+), 2 deletions(-)
+
+diff --git a/block/nvme.c b/block/nvme.c
+index e4f336d79c..fa360b9b3c 100644
+--- a/block/nvme.c
+++ b/block/nvme.c
+@@ -206,8 +206,9 @@ static void nvme_free_req_queue_cb(void *opaque)
+     NVMeQueuePair *q = opaque;
+ 
+     qemu_mutex_lock(&q->lock);
+-    while (qemu_co_enter_next(&q->free_req_queue, &q->lock)) {
+-        /* Retry all pending requests */
+    while (q->free_req_head != -1 &&
+           qemu_co_enter_next(&q->free_req_queue, &q->lock)) {
+        /* Retry waiting requests */
+     }
+     qemu_mutex_unlock(&q->lock);
+ }
+-- 
+2.27.0
+
--- a/kvm-rhel-machine-types-x86-set-prefer_sockets.patch
+++ b/kvm-rhel-machine-types-x86-set-prefer_sockets.patch
@ -0,0 +1,52 @@
+From ecadfaec992fda7f485522c9ee6e7c9b05614a22 Mon Sep 17 00:00:00 2001
+From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
+Date: Tue, 7 Dec 2021 18:39:47 +0000
+Subject: [PATCH 2/2] rhel machine types/x86: set prefer_sockets
+
+RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
+RH-MergeRequest: 59: rhel machine types/x86: set prefer_sockets
+RH-Commit: [1/1] 9bcd9e2c95154e39ef30a8a342ad6c713fa4f1fb (dagrh/c-9-s-qemu-kvm)
+RH-Bugzilla: 2028623
+RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
+RH-Acked-by: quintela1 <quintela@redhat.com>
+RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
+
+When I fixed up the machine types for 8.5 I missed the
+  prefer_sockets = true
+
+add them in; it looks like Power, ARM already have them, and I see them
+in thuth's s390 patch.
+
+Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
+---
+ hw/i386/pc_piix.c | 1 +
+ hw/i386/pc_q35.c  | 1 +
+ 2 files changed, 2 insertions(+)
+
+diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
+index 183b5d5464..fccb7f5fc9 100644
+--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
+@@ -973,6 +973,7 @@ static void pc_machine_rhel7_options(MachineClass *m)
+     compat_props_add(m->compat_props, pc_rhel_compat, pc_rhel_compat_len);
+     m->alias = "pc";
+     m->is_default = 1;
+    m->smp_props.prefer_sockets = true;
+ }
+ 
+ static void pc_init_rhel760(MachineState *machine)
+diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
+index 0e7e885e78..3b748ddd7b 100644
+--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
+@@ -662,6 +662,7 @@ static void pc_q35_machine_rhel850_options(MachineClass *m)
+                      hw_compat_rhel_8_5_len);
+     compat_props_add(m->compat_props, pc_rhel_8_5_compat,
+                      pc_rhel_8_5_compat_len);
+    m->smp_props.prefer_sockets = true;
+ }
+ 
+ DEFINE_PC_MACHINE(q35_rhel850, "pc-q35-rhel8.5.0", pc_q35_init_rhel850,
+-- 
+2.27.0
+
--- a/qemu-kvm.spec
+++ b/qemu-kvm.spec
@ -130,7 +130,7 @@ Obsoletes: %{name}-block-iscsi <= %{version}                    \
 Summary: QEMU is a machine emulator and virtualizer
 Name: qemu-kvm
 Version: 6.2.0
-Release: 3%{?rcrel}%{?dist}%{?cc_suffix}
+Release: 4%{?rcrel}%{?dist}%{?cc_suffix}
 # Epoch because we pushed a qemu-1.0 package. AIUI this can't ever be dropped
 # Epoch 15 used for RHEL 8
 # Epoch 17 used for RHEL 9 (due to release versioning offset in RHEL 8.5)
@ -193,6 +193,12 @@ Patch31: kvm-hw-arm-virt-Expose-the-RAS-option.patch
 Patch32: kvm-hw-arm-virt-Add-9.0-machine-type-and-remove-8.5-one.patch
 # For bz#2031044 - Add rhel-9.0.0 machine types for RHEL 9.0 [aarch64]
 Patch33: kvm-hw-arm-virt-Check-no_tcg_its-and-minor-style-changes.patch
+# For bz#2024544 - Fio workers hangs when running fio with 32 jobs iodepth 32 and QEMU's userspace NVMe driver
+Patch34: kvm-block-nvme-fix-infinite-loop-in-nvme_free_req_queue_.patch
+# For bz#2028623 - [9.0] machine types: 6.2: Fix prefer_sockets
+Patch35: kvm-rhel-machine-types-x86-set-prefer_sockets.patch
+
+# Source-git patches

 %if %{have_clang}
 BuildRequires: clang
@ -1171,6 +1177,14 @@ useradd -r -u 107 -g qemu -G kvm -d / -s /sbin/nologin \
 %endif

 %changelog
+* Mon Jan 17 2022 Miroslav Rezanina <mrezanin@redhat.com> - 6.2.0-4
+- kvm-block-nvme-fix-infinite-loop-in-nvme_free_req_queue_.patch [bz#2024544]
+- kvm-rhel-machine-types-x86-set-prefer_sockets.patch [bz#2028623]
+- Resolves: bz#2024544
+  (Fio workers hangs when running fio with 32 jobs iodepth 32 and QEMU's userspace NVMe driver)
+- Resolves: bz#2028623
+  ([9.0] machine types: 6.2: Fix prefer_sockets)
+
 * Mon Jan 10 2022 Miroslav Rezanina <mrezanin@redhat.com> - 6.2.0-3
 - kvm-hw-arm-virt-Register-iommu-as-a-class-property.patch [bz#2031044]
 - kvm-hw-arm-virt-Register-its-as-a-class-property.patch [bz#2031044]