qemu-kvm/kvm-hw-net-rtl8139-skip-automatic-zero-init-of-large-arr.patch
Miroslav Rezanina bd7b93c113 * Tue Jul 08 2025 Miroslav Rezanina <mrezanin@redhat.com> - 9.1.0-25
- kvm-s390x-Fix-leak-in-machine_set_loadparm.patch [RHEL-98554]
- kvm-hw-s390x-ccw-device-Fix-memory-leak-in-loadparm-sett.patch [RHEL-98554]
- kvm-amd_iommu-Rename-variable-mmio-to-mr_mmio.patch [RHEL-66202]
- kvm-amd_iommu-Add-support-for-pass-though-mode.patch [RHEL-66202]
- kvm-amd_iommu-Use-shared-memory-region-for-Interrupt-Rem.patch [RHEL-66202]
- kvm-amd_iommu-Send-notification-when-invalidate-interrup.patch [RHEL-66202]
- kvm-amd_iommu-Check-APIC-ID-255-for-XTSup.patch [RHEL-66202]
- kvm-io-Fix-partial-struct-copy-in-qio_dns_resolver_looku.patch [RHEL-67104]
- kvm-util-qemu-sockets-Refactor-setting-client-sockopts-i.patch [RHEL-67104]
- kvm-util-qemu-sockets-Refactor-success-and-failure-paths.patch [RHEL-67104]
- kvm-util-qemu-sockets-Add-support-for-keep-alive-flag-to.patch [RHEL-67104]
- kvm-util-qemu-sockets-Refactor-inet_parse-to-use-QemuOpt.patch [RHEL-67104]
- kvm-util-qemu-sockets-Introduce-inet-socket-options-cont.patch [RHEL-67104]
- kvm-tests-unit-test-util-sockets-fix-mem-leak-on-error-o.patch [RHEL-67104]
- kvm-target-i386-Expose-bits-related-to-SRSO-vulnerabilit.patch [RHEL-52649]
- kvm-target-i386-Add-PerfMonV2-feature-bit.patch [RHEL-52649]
- kvm-target-i386-Update-EPYC-CPU-model-for-Cache-property.patch [RHEL-52649]
- kvm-target-i386-Update-EPYC-Rome-CPU-model-for-Cache-pro.patch [RHEL-52649]
- kvm-target-i386-Update-EPYC-Milan-CPU-model-for-Cache-pr.patch [RHEL-52649]
- kvm-target-i386-Add-couple-of-feature-bits-in-CPUID_Fn80.patch [RHEL-52649]
- kvm-target-i386-Update-EPYC-Genoa-for-Cache-property-per.patch [RHEL-52649]
- kvm-target-i386-Add-support-for-EPYC-Turin-model.patch [RHEL-52649]
- kvm-hw-i386-amd_iommu-Assign-pci-id-0x1419-for-the-AMD-I.patch [RHEL-70926]
- kvm-hw-i386-amd_iommu-Isolate-AMDVI-PCI-from-amd-iommu-d.patch [RHEL-70925]
- kvm-hw-i386-amd_iommu-Allow-migration-when-explicitly-cr.patch [RHEL-70925]
- kvm-Enable-amd-iommu-device.patch [RHEL-70925]
- kvm-include-qemu-compiler-add-QEMU_UNINITIALIZED-attribu.patch [RHEL-99888]
- kvm-hw-virtio-virtio-avoid-cost-of-ftrivial-auto-var-ini.patch [RHEL-99888]
- kvm-block-skip-automatic-zero-init-of-large-array-in-ioq.patch [RHEL-99888]
- kvm-chardev-char-fd-skip-automatic-zero-init-of-large-ar.patch [RHEL-99888]
- kvm-chardev-char-pty-skip-automatic-zero-init-of-large-a.patch [RHEL-99888]
- kvm-chardev-char-socket-skip-automatic-zero-init-of-larg.patch [RHEL-99888]
- kvm-hw-audio-ac97-skip-automatic-zero-init-of-large-arra.patch [RHEL-99888]
- kvm-hw-audio-cs4231a-skip-automatic-zero-init-of-large-a.patch [RHEL-99888]
- kvm-hw-audio-es1370-skip-automatic-zero-init-of-large-ar.patch [RHEL-99888]
- kvm-hw-audio-gus-skip-automatic-zero-init-of-large-array.patch [RHEL-99888]
- kvm-hw-audio-marvell_88w8618-skip-automatic-zero-init-of.patch [RHEL-99888]
- kvm-hw-audio-sb16-skip-automatic-zero-init-of-large-arra.patch [RHEL-99888]
- kvm-hw-audio-via-ac97-skip-automatic-zero-init-of-large-.patch [RHEL-99888]
- kvm-hw-char-sclpconsole-lm-skip-automatic-zero-init-of-l.patch [RHEL-99888]
- kvm-hw-dma-xlnx_csu_dma-skip-automatic-zero-init-of-larg.patch [RHEL-99888]
- kvm-hw-display-vmware_vga-skip-automatic-zero-init-of-la.patch [RHEL-99888]
- kvm-hw-hyperv-syndbg-skip-automatic-zero-init-of-large-a.patch [RHEL-99888]
- kvm-hw-misc-aspeed_hace-skip-automatic-zero-init-of-larg.patch [RHEL-99888]
- kvm-hw-net-rtl8139-skip-automatic-zero-init-of-large-arr.patch [RHEL-99888]
- kvm-hw-net-tulip-skip-automatic-zero-init-of-large-array.patch [RHEL-99888]
- kvm-hw-net-virtio-net-skip-automatic-zero-init-of-large-.patch [RHEL-99888]
- kvm-hw-net-xgamc-skip-automatic-zero-init-of-large-array.patch [RHEL-99888]
- kvm-hw-nvme-ctrl-skip-automatic-zero-init-of-large-array.patch [RHEL-99888]
- kvm-hw-ppc-spapr_tpm_proxy-skip-automatic-zero-init-of-l.patch [RHEL-99888]
- kvm-hw-usb-hcd-ohci-skip-automatic-zero-init-of-large-ar.patch [RHEL-99888]
- kvm-hw-scsi-lsi53c895a-skip-automatic-zero-init-of-large.patch [RHEL-99888]
- kvm-hw-scsi-megasas-skip-automatic-zero-init-of-large-ar.patch [RHEL-99888]
- kvm-hw-ufs-lu-skip-automatic-zero-init-of-large-array.patch [RHEL-99888]
- kvm-net-socket-skip-automatic-zero-init-of-large-array.patch [RHEL-99888]
- kvm-net-stream-skip-automatic-zero-init-of-large-array.patch [RHEL-99888]
- kvm-ui-vnc-Update-display-update-interval-when-VM-state-.patch [RHEL-100741]
- Resolves: RHEL-98554
  ([s390x][RHEL9.7.0][virtio_block] there would be memory leak with virtio_blk disks)
- Resolves: RHEL-66202
  ([AMDSERVER 9.6 Feature] qemu: Interrupt Remap support for emulated amd viommu)
- Resolves: RHEL-67104
  (postcopy on the destination host can't switch into pause status under the network issue if boot VM with '-S')
- Resolves: RHEL-52649
  ([AMDSERVER 9.6 Feature] Turin: Qemu EPYC-Turin Model)
- Resolves: RHEL-70926
  (Qemu/amd-iommu: Advertise a suitable device id)
- Resolves: RHEL-70925
  (Qemu/amd-iommu: Add ability to manually specify the AMDVI-PCI device)
- Resolves: RHEL-99888
  (-ftrivial-auto-var-init=zero reduced performance [rhel-9])
- Resolves: RHEL-100741
  (Video stuck after switchover phase when play one video during migration [rhel-9])
2025-07-08 02:53:14 -04:00

49 lines
1.8 KiB
Diff

From cc173deaaa4d9dc6ad9188e0b03f46b7e64f26b2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= <berrange@redhat.com>
Date: Tue, 10 Jun 2025 13:36:57 +0100
Subject: [PATCH 45/57] hw/net/rtl8139: skip automatic zero-init of large array
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
RH-Author: Stefan Hajnoczi <stefanha@redhat.com>
RH-MergeRequest: 382: Solve -ftrivial-auto-var-init performance regression with QEMU_UNINITIALIZED
RH-Jira: RHEL-99888
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Commit: [19/30] 344c720aef2feb35f84fd4b21f2b1b31e5572286 (stefanha/centos-stream-qemu-kvm)
The 'rtl8139_transmit_one' method has a 8k byte array used for
copying data between guest and host. Skip the automatic zero-init
of this array to eliminate the performance overhead in the I/O
hot path.
The 'txbuffer' will be fully initialized when reading PCI DMA
buffers.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20250610123709.835102-20-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit 3ccc6489dd4925ddd1f3066bd3751389169cd7aa)
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
hw/net/rtl8139.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/net/rtl8139.c b/hw/net/rtl8139.c
index f2fe057535..a2732bf1c1 100644
--- a/hw/net/rtl8139.c
+++ b/hw/net/rtl8139.c
@@ -1818,7 +1818,7 @@ static int rtl8139_transmit_one(RTL8139State *s, int descriptor)
PCIDevice *d = PCI_DEVICE(s);
int txsize = s->TxStatus[descriptor] & 0x1fff;
- uint8_t txbuffer[0x2000];
+ QEMU_UNINITIALIZED uint8_t txbuffer[0x2000];
DPRINTF("+++ transmit reading %d bytes from host memory at 0x%08x\n",
txsize, s->TxAddr[descriptor]);
--
2.39.3