From: Sergio Lopez <slp@redhat.com> To: qemu-devel@nongnu.org Cc: "Christian Borntraeger" <borntraeger@linux.ibm.com>, "Alex Williamson" <alex.williamson@redhat.com>, "Cornelia Huck" <cohuck@redhat.com>, "Thomas Huth" <thuth@redhat.com>, "Paolo Bonzini" <pbonzini@redhat.com>, "Stefan Hajnoczi" <stefanha@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, "David Hildenbrand" <david@redhat.com>, "Elena Ufimtseva" <elena.ufimtseva@oracle.com>, kvm@vger.kernel.org, "Halil Pasic" <pasic@linux.ibm.com>, "Fam Zheng" <fam@euphon.net>, "John G Johnson" <john.g.johnson@oracle.com>, "Richard Henderson" <richard.henderson@linaro.org>, "Matthew Rosato" <mjrosato@linux.ibm.com>, "Hanna Reitz" <hreitz@redhat.com>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, qemu-s390x@nongnu.org, vgoyal@redhat.com, "Jagannathan Raman" <jag.raman@oracle.com>, "Kevin Wolf" <kwolf@redhat.com>, qemu-block@nongnu.org, "Eric Farman" <farman@linux.ibm.com>, "Sergio Lopez" <slp@redhat.com> Subject: [PATCH v3 1/4] event_notifier: add event_notifier_get_wfd() Date: Thu, 3 Mar 2022 12:59:08 +0100 [thread overview] Message-ID: <20220303115911.20962-2-slp@redhat.com> (raw) In-Reply-To: <20220303115911.20962-1-slp@redhat.com> event_notifier_get_fd(const EventNotifier *e) always returns EventNotifier's read file descriptor (rfd). This is not a problem when the EventNotifier is backed by a an eventfd, as a single file descriptor is used both for reading and triggering events (rfd == wfd). But, when EventNotifier is backed by a pipe pair, we have two file descriptors, one that can only be used for reads (rfd), and the other only for writes (wfd). There's, at least, one known situation in which we need to obtain wfd instead of rfd, which is when setting up the file that's going to be sent to the peer in vhost's SET_VRING_CALL. Add a new event_notifier_get_wfd(const EventNotifier *e) that can be used to obtain wfd where needed. Signed-off-by: Sergio Lopez <slp@redhat.com> --- include/qemu/event_notifier.h | 1 + util/event_notifier-posix.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/include/qemu/event_notifier.h b/include/qemu/event_notifier.h index b79add035d..8a4ff308e1 100644 --- a/include/qemu/event_notifier.h +++ b/include/qemu/event_notifier.h @@ -38,6 +38,7 @@ int event_notifier_test_and_clear(EventNotifier *); #ifdef CONFIG_POSIX void event_notifier_init_fd(EventNotifier *, int fd); int event_notifier_get_fd(const EventNotifier *); +int event_notifier_get_wfd(const EventNotifier *); #else HANDLE event_notifier_get_handle(EventNotifier *); #endif diff --git a/util/event_notifier-posix.c b/util/event_notifier-posix.c index 8307013c5d..16294e98d4 100644 --- a/util/event_notifier-posix.c +++ b/util/event_notifier-posix.c @@ -99,6 +99,11 @@ int event_notifier_get_fd(const EventNotifier *e) return e->rfd; } +int event_notifier_get_wfd(const EventNotifier *e) +{ + return e->wfd; +} + int event_notifier_set(EventNotifier *e) { static const uint64_t value = 1; -- 2.35.1
WARNING: multiple messages have this Message-ID (diff)
From: Sergio Lopez <slp@redhat.com> To: qemu-devel@nongnu.org Cc: "Elena Ufimtseva" <elena.ufimtseva@oracle.com>, "Fam Zheng" <fam@euphon.net>, "Matthew Rosato" <mjrosato@linux.ibm.com>, "John G Johnson" <john.g.johnson@oracle.com>, "David Hildenbrand" <david@redhat.com>, "Eric Farman" <farman@linux.ibm.com>, "Alex Williamson" <alex.williamson@redhat.com>, kvm@vger.kernel.org, qemu-block@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>, "Halil Pasic" <pasic@linux.ibm.com>, "Christian Borntraeger" <borntraeger@linux.ibm.com>, vgoyal@redhat.com, "Thomas Huth" <thuth@redhat.com>, "Sergio Lopez" <slp@redhat.com>, "Richard Henderson" <richard.henderson@linaro.org>, qemu-s390x@nongnu.org, "Stefan Hajnoczi" <stefanha@redhat.com>, "Jagannathan Raman" <jag.raman@oracle.com>, "Kevin Wolf" <kwolf@redhat.com>, "Cornelia Huck" <cohuck@redhat.com>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, "Hanna Reitz" <hreitz@redhat.com>, "Paolo Bonzini" <pbonzini@redhat.com> Subject: [PATCH v3 1/4] event_notifier: add event_notifier_get_wfd() Date: Thu, 3 Mar 2022 12:59:08 +0100 [thread overview] Message-ID: <20220303115911.20962-2-slp@redhat.com> (raw) In-Reply-To: <20220303115911.20962-1-slp@redhat.com> event_notifier_get_fd(const EventNotifier *e) always returns EventNotifier's read file descriptor (rfd). This is not a problem when the EventNotifier is backed by a an eventfd, as a single file descriptor is used both for reading and triggering events (rfd == wfd). But, when EventNotifier is backed by a pipe pair, we have two file descriptors, one that can only be used for reads (rfd), and the other only for writes (wfd). There's, at least, one known situation in which we need to obtain wfd instead of rfd, which is when setting up the file that's going to be sent to the peer in vhost's SET_VRING_CALL. Add a new event_notifier_get_wfd(const EventNotifier *e) that can be used to obtain wfd where needed. Signed-off-by: Sergio Lopez <slp@redhat.com> --- include/qemu/event_notifier.h | 1 + util/event_notifier-posix.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/include/qemu/event_notifier.h b/include/qemu/event_notifier.h index b79add035d..8a4ff308e1 100644 --- a/include/qemu/event_notifier.h +++ b/include/qemu/event_notifier.h @@ -38,6 +38,7 @@ int event_notifier_test_and_clear(EventNotifier *); #ifdef CONFIG_POSIX void event_notifier_init_fd(EventNotifier *, int fd); int event_notifier_get_fd(const EventNotifier *); +int event_notifier_get_wfd(const EventNotifier *); #else HANDLE event_notifier_get_handle(EventNotifier *); #endif diff --git a/util/event_notifier-posix.c b/util/event_notifier-posix.c index 8307013c5d..16294e98d4 100644 --- a/util/event_notifier-posix.c +++ b/util/event_notifier-posix.c @@ -99,6 +99,11 @@ int event_notifier_get_fd(const EventNotifier *e) return e->rfd; } +int event_notifier_get_wfd(const EventNotifier *e) +{ + return e->wfd; +} + int event_notifier_set(EventNotifier *e) { static const uint64_t value = 1; -- 2.35.1
next prev parent reply other threads:[~2022-03-03 12:00 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-03-03 11:59 [PATCH v3 0/4] Enable vhost-user to be used on BSD systems Sergio Lopez 2022-03-03 11:59 ` Sergio Lopez 2022-03-03 11:59 ` Sergio Lopez [this message] 2022-03-03 11:59 ` [PATCH v3 1/4] event_notifier: add event_notifier_get_wfd() Sergio Lopez 2022-03-03 11:59 ` [PATCH v3 2/4] vhost: use wfd on functions setting vring call fd Sergio Lopez 2022-03-03 11:59 ` Sergio Lopez 2022-03-03 11:59 ` [PATCH v3 3/4] configure, meson: allow enabling vhost-user on all POSIX systems Sergio Lopez 2022-03-03 11:59 ` Sergio Lopez 2022-03-03 11:59 ` [PATCH v3 4/4] docs: vhost-user: add subsection for non-Linux platforms Sergio Lopez 2022-03-03 11:59 ` Sergio Lopez 2022-03-03 14:34 ` Stefan Hajnoczi 2022-03-03 14:34 ` Stefan Hajnoczi 2022-03-04 10:35 ` Michael S. Tsirkin 2022-03-04 10:35 ` Michael S. Tsirkin 2022-03-04 10:50 ` Sergio Lopez 2022-03-04 10:50 ` Sergio Lopez 2022-03-03 14:35 ` [PATCH v3 0/4] Enable vhost-user to be used on BSD systems Stefan Hajnoczi 2022-03-03 14:35 ` Stefan Hajnoczi 2022-03-04 10:38 ` Michael S. Tsirkin 2022-03-04 10:38 ` Michael S. Tsirkin
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