qemu-kvm/kvm-coroutine-ucontext-use-QEMU_DEFINE_STATIC_CO_TLS.patch
Miroslav Rezanina 0ddb1bc433 * Mon Jun 27 2022 Miroslav Rezanina <mrezanin@redhat.com> - 7.0.0-7
- kvm-coroutine-ucontext-use-QEMU_DEFINE_STATIC_CO_TLS.patch [bz#1952483]
- kvm-coroutine-use-QEMU_DEFINE_STATIC_CO_TLS.patch [bz#1952483]
- kvm-coroutine-win32-use-QEMU_DEFINE_STATIC_CO_TLS.patch [bz#1952483]
- kvm-Enable-virtio-iommu-pci-on-x86_64.patch [bz#2094252]
- kvm-linux-aio-fix-unbalanced-plugged-counter-in-laio_io_.patch [bz#2092788]
- kvm-linux-aio-explain-why-max-batch-is-checked-in-laio_i.patch [bz#2092788]
- Resolves: bz#1952483
  (RFE: QEMU's coroutines fail with CFLAGS=-flto on non-x86_64 architectures)
- Resolves: bz#2094252
  (Compile the virtio-iommu device on x86_64)
- Resolves: bz#2092788
  (Stalled IO Operations in VM)
2022-06-27 04:48:14 -04:00

133 lines
4.4 KiB
Diff

From ffbd90e5f4eba620c7cd631b04f0ed31beb22ffa Mon Sep 17 00:00:00 2001
From: Stefan Hajnoczi <stefanha@redhat.com>
Date: Tue, 17 May 2022 12:07:56 +0100
Subject: [PATCH 1/6] coroutine-ucontext: use QEMU_DEFINE_STATIC_CO_TLS()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
RH-Author: Stefan Hajnoczi <stefanha@redhat.com>
RH-MergeRequest: 89: coroutine: use coroutine TLS macros to protect thread-local variables
RH-Commit: [1/3] a9782fe8e919c4bd317b7e8744c7ff57d898add3 (stefanha/centos-stream-qemu-kvm)
RH-Bugzilla: 1952483
RH-Acked-by: Hanna Reitz <hreitz@redhat.com>
RH-Acked-by: Eric Blake <eblake@redhat.com>
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
Thread-Local Storage variables cannot be used directly from coroutine
code because the compiler may optimize TLS variable accesses across
qemu_coroutine_yield() calls. When the coroutine is re-entered from
another thread the TLS variables from the old thread must no longer be
used.
Use QEMU_DEFINE_STATIC_CO_TLS() for the current and leader variables.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220307153853.602859-2-stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 34145a307d849d0b6734d0222a7aa0bb9eef7407)
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
util/coroutine-ucontext.c | 38 ++++++++++++++++++++++++--------------
1 file changed, 24 insertions(+), 14 deletions(-)
diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c
index 904b375192..127d5a13c8 100644
--- a/util/coroutine-ucontext.c
+++ b/util/coroutine-ucontext.c
@@ -25,6 +25,7 @@
#include "qemu/osdep.h"
#include <ucontext.h>
#include "qemu/coroutine_int.h"
+#include "qemu/coroutine-tls.h"
#ifdef CONFIG_VALGRIND_H
#include <valgrind/valgrind.h>
@@ -66,8 +67,8 @@ typedef struct {
/**
* Per-thread coroutine bookkeeping
*/
-static __thread CoroutineUContext leader;
-static __thread Coroutine *current;
+QEMU_DEFINE_STATIC_CO_TLS(Coroutine *, current);
+QEMU_DEFINE_STATIC_CO_TLS(CoroutineUContext, leader);
/*
* va_args to makecontext() must be type 'int', so passing
@@ -97,14 +98,15 @@ static inline __attribute__((always_inline))
void finish_switch_fiber(void *fake_stack_save)
{
#ifdef CONFIG_ASAN
+ CoroutineUContext *leaderp = get_ptr_leader();
const void *bottom_old;
size_t size_old;
__sanitizer_finish_switch_fiber(fake_stack_save, &bottom_old, &size_old);
- if (!leader.stack) {
- leader.stack = (void *)bottom_old;
- leader.stack_size = size_old;
+ if (!leaderp->stack) {
+ leaderp->stack = (void *)bottom_old;
+ leaderp->stack_size = size_old;
}
#endif
#ifdef CONFIG_TSAN
@@ -161,8 +163,10 @@ static void coroutine_trampoline(int i0, int i1)
/* Initialize longjmp environment and switch back the caller */
if (!sigsetjmp(self->env, 0)) {
- start_switch_fiber_asan(COROUTINE_YIELD, &fake_stack_save, leader.stack,
- leader.stack_size);
+ CoroutineUContext *leaderp = get_ptr_leader();
+
+ start_switch_fiber_asan(COROUTINE_YIELD, &fake_stack_save,
+ leaderp->stack, leaderp->stack_size);
start_switch_fiber_tsan(&fake_stack_save, self, true); /* true=caller */
siglongjmp(*(sigjmp_buf *)co->entry_arg, 1);
}
@@ -297,7 +301,7 @@ qemu_coroutine_switch(Coroutine *from_, Coroutine *to_,
int ret;
void *fake_stack_save = NULL;
- current = to_;
+ set_current(to_);
ret = sigsetjmp(from->env, 0);
if (ret == 0) {
@@ -315,18 +319,24 @@ qemu_coroutine_switch(Coroutine *from_, Coroutine *to_,
Coroutine *qemu_coroutine_self(void)
{
- if (!current) {
- current = &leader.base;
+ Coroutine *self = get_current();
+ CoroutineUContext *leaderp = get_ptr_leader();
+
+ if (!self) {
+ self = &leaderp->base;
+ set_current(self);
}
#ifdef CONFIG_TSAN
- if (!leader.tsan_co_fiber) {
- leader.tsan_co_fiber = __tsan_get_current_fiber();
+ if (!leaderp->tsan_co_fiber) {
+ leaderp->tsan_co_fiber = __tsan_get_current_fiber();
}
#endif
- return current;
+ return self;
}
bool qemu_in_coroutine(void)
{
- return current && current->caller;
+ Coroutine *self = get_current();
+
+ return self && self->caller;
}
--
2.31.1