PR/59618 CVS commit: src

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

The following reply was made to PR kern/59618; it has been noted by GNATS.

From: "Taylor R Campbell" <riastradh%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/59618 CVS commit: src
Date: Sat, 6 Sep 2025 02:53:24 +0000

 Module Name:	src
 Committed By:	riastradh
 Date:		Sat Sep  6 02:53:23 UTC 2025
 
 Modified Files:
 	src/common/lib/libc/arch/i386/atomic: atomic.S
 	src/common/lib/libc/arch/sparc/atomic: membar_ops.S
 	src/common/lib/libc/arch/sparc64/atomic: membar_ops.S
 	src/common/lib/libc/arch/x86_64/atomic: atomic.S
 	src/distrib/sets/lists/comp: mi
 	src/share/man/man9: Makefile
 	src/sys/arch/alpha/alpha: locore.s
 	src/sys/arch/amd64/amd64: cpufunc.S
 	src/sys/arch/arm/arm: cpu_subr.c
 	src/sys/arch/hppa/hppa: support.S
 	src/sys/arch/i386/i386: cpufunc.S
 	src/sys/arch/mips/mips: cpu_subr.c
 	src/sys/arch/riscv/riscv: cpu_subr.c
 	src/sys/arch/sparc/sparc: locore.s
 	src/sys/arch/sparc64/sparc64: locore.s
 	src/sys/arch/virt68k/virt68k: locore.s
 Added Files:
 	src/share/man/man9: paravirt_membar_sync.9
 	src/sys/sys: paravirt_membar.h
 
 Log Message:
 paravirt_membar_sync(9): New memory barrier.
 
 For use in paravirtualized drivers which require store-before-load
 ordering -- irrespective of whether the kernel is built for a single
 processor, or whether the (virtual) machine is booted with a single
 processor.
 
 This is even required on architectures that don't even have a
 store-before-load ordering barrier, like m68k; adding, e.g., a virtio
 bus is _as if_ the architecture has been extended with relaxed memory
 ordering when talking with that new bus.  Such architectures need
 some way to request the hypervisor enforce that ordering -- on m68k,
 that's done by issuing a CASL instruction, which qemu maps to an
 atomic r/m/w with sequential consistency ordering in the host.
 
 PR kern/59618: occasional virtio block device lock ups/hangs
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.37 -r1.38 src/common/lib/libc/arch/i386/atomic/atomic.S
 cvs rdiff -u -r1.8 -r1.9 src/common/lib/libc/arch/sparc/atomic/membar_ops.S
 cvs rdiff -u -r1.9 -r1.10 \
     src/common/lib/libc/arch/sparc64/atomic/membar_ops.S
 cvs rdiff -u -r1.31 -r1.32 src/common/lib/libc/arch/x86_64/atomic/atomic.S
 cvs rdiff -u -r1.2498 -r1.2499 src/distrib/sets/lists/comp/mi
 cvs rdiff -u -r1.474 -r1.475 src/share/man/man9/Makefile
 cvs rdiff -u -r0 -r1.1 src/share/man/man9/paravirt_membar_sync.9
 cvs rdiff -u -r1.144 -r1.145 src/sys/arch/alpha/alpha/locore.s
 cvs rdiff -u -r1.69 -r1.70 src/sys/arch/amd64/amd64/cpufunc.S
 cvs rdiff -u -r1.5 -r1.6 src/sys/arch/arm/arm/cpu_subr.c
 cvs rdiff -u -r1.8 -r1.9 src/sys/arch/hppa/hppa/support.S
 cvs rdiff -u -r1.53 -r1.54 src/sys/arch/i386/i386/cpufunc.S
 cvs rdiff -u -r1.64 -r1.65 src/sys/arch/mips/mips/cpu_subr.c
 cvs rdiff -u -r1.5 -r1.6 src/sys/arch/riscv/riscv/cpu_subr.c
 cvs rdiff -u -r1.286 -r1.287 src/sys/arch/sparc/sparc/locore.s
 cvs rdiff -u -r1.435 -r1.436 src/sys/arch/sparc64/sparc64/locore.s
 cvs rdiff -u -r1.16 -r1.17 src/sys/arch/virt68k/virt68k/locore.s
 cvs rdiff -u -r0 -r1.1 src/sys/sys/paravirt_membar.h
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.