From: Stefano Stabellini <sstabellini@kernel.org> To: peter.maydell@linaro.org, stefanha@gmail.com Cc: sstabellini@kernel.org, stefanha@redhat.com, anthony.perard@citrix.com, xen-devel@lists.xenproject.org, qemu-devel@nongnu.org, Paul Durrant <paul.durrant@citrix.com> Subject: [Qemu-devel] [PULL 2/3] xen-disk: only advertize feature-persistent if grant copy is not available Date: Tue, 27 Jun 2017 15:04:42 -0700 [thread overview] Message-ID: <1498601083-11799-2-git-send-email-sstabellini@kernel.org> (raw) In-Reply-To: <1498601083-11799-1-git-send-email-sstabellini@kernel.org> From: Paul Durrant <paul.durrant@citrix.com> If grant copy is available then it will always be used in preference to persistent maps. In this case feature-persistent should not be advertized to the frontend, otherwise it may needlessly copy data into persistently granted buffers. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> --- hw/block/xen_disk.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c index 9200511..8218741 100644 --- a/hw/block/xen_disk.c +++ b/hw/block/xen_disk.c @@ -1022,11 +1022,18 @@ static int blk_init(struct XenDevice *xendev) blkdev->file_blk = BLOCK_SIZE; + blkdev->feature_grant_copy = + (xengnttab_grant_copy(blkdev->xendev.gnttabdev, 0, NULL) == 0); + + xen_pv_printf(&blkdev->xendev, 3, "grant copy operation %s\n", + blkdev->feature_grant_copy ? "enabled" : "disabled"); + /* fill info * blk_connect supplies sector-size and sectors */ xenstore_write_be_int(&blkdev->xendev, "feature-flush-cache", 1); - xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1); + xenstore_write_be_int(&blkdev->xendev, "feature-persistent", + !blkdev->feature_grant_copy); xenstore_write_be_int(&blkdev->xendev, "info", info); blk_parse_discard(blkdev); @@ -1201,12 +1208,6 @@ static int blk_connect(struct XenDevice *xendev) xen_be_bind_evtchn(&blkdev->xendev); - blkdev->feature_grant_copy = - (xengnttab_grant_copy(blkdev->xendev.gnttabdev, 0, NULL) == 0); - - xen_pv_printf(&blkdev->xendev, 3, "grant copy operation %s\n", - blkdev->feature_grant_copy ? "enabled" : "disabled"); - xen_pv_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, " "remote port %d, local port %d\n", blkdev->xendev.protocol, blkdev->ring_ref, -- 1.9.1
WARNING: multiple messages have this Message-ID (diff)
From: Stefano Stabellini <sstabellini@kernel.org> To: peter.maydell@linaro.org, stefanha@gmail.com Cc: sstabellini@kernel.org, qemu-devel@nongnu.org, Paul Durrant <paul.durrant@citrix.com>, stefanha@redhat.com, anthony.perard@citrix.com, xen-devel@lists.xenproject.org Subject: [PULL 2/3] xen-disk: only advertize feature-persistent if grant copy is not available Date: Tue, 27 Jun 2017 15:04:42 -0700 [thread overview] Message-ID: <1498601083-11799-2-git-send-email-sstabellini@kernel.org> (raw) In-Reply-To: <1498601083-11799-1-git-send-email-sstabellini@kernel.org> From: Paul Durrant <paul.durrant@citrix.com> If grant copy is available then it will always be used in preference to persistent maps. In this case feature-persistent should not be advertized to the frontend, otherwise it may needlessly copy data into persistently granted buffers. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> --- hw/block/xen_disk.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c index 9200511..8218741 100644 --- a/hw/block/xen_disk.c +++ b/hw/block/xen_disk.c @@ -1022,11 +1022,18 @@ static int blk_init(struct XenDevice *xendev) blkdev->file_blk = BLOCK_SIZE; + blkdev->feature_grant_copy = + (xengnttab_grant_copy(blkdev->xendev.gnttabdev, 0, NULL) == 0); + + xen_pv_printf(&blkdev->xendev, 3, "grant copy operation %s\n", + blkdev->feature_grant_copy ? "enabled" : "disabled"); + /* fill info * blk_connect supplies sector-size and sectors */ xenstore_write_be_int(&blkdev->xendev, "feature-flush-cache", 1); - xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1); + xenstore_write_be_int(&blkdev->xendev, "feature-persistent", + !blkdev->feature_grant_copy); xenstore_write_be_int(&blkdev->xendev, "info", info); blk_parse_discard(blkdev); @@ -1201,12 +1208,6 @@ static int blk_connect(struct XenDevice *xendev) xen_be_bind_evtchn(&blkdev->xendev); - blkdev->feature_grant_copy = - (xengnttab_grant_copy(blkdev->xendev.gnttabdev, 0, NULL) == 0); - - xen_pv_printf(&blkdev->xendev, 3, "grant copy operation %s\n", - blkdev->feature_grant_copy ? "enabled" : "disabled"); - xen_pv_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, " "remote port %d, local port %d\n", blkdev->xendev.protocol, blkdev->ring_ref, -- 1.9.1 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
next prev parent reply other threads:[~2017-06-27 22:04 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-06-27 22:04 [Qemu-devel] [PATCH 0/3] please pull xen-20170627-tag Stefano Stabellini 2017-06-27 22:04 ` Stefano Stabellini 2017-06-27 22:04 ` [Qemu-devel] [PULL 1/3] xen/disk: don't leak stack data via response ring Stefano Stabellini 2017-06-27 22:04 ` Stefano Stabellini 2017-06-27 22:04 ` Stefano Stabellini [this message] 2017-06-27 22:04 ` [PULL 2/3] xen-disk: only advertize feature-persistent if grant copy is not available Stefano Stabellini 2017-06-27 22:04 ` [Qemu-devel] [PULL 3/3] xen-disk: add support for multi-page shared rings Stefano Stabellini 2017-06-27 22:04 ` Stefano Stabellini 2017-07-27 6:02 ` [Qemu-devel] [Xen-devel] " Olaf Hering 2017-07-27 6:02 ` Olaf Hering 2017-07-27 19:14 ` [Qemu-devel] [Xen-devel] " Stefano Stabellini 2017-07-27 19:14 ` [Qemu-devel] " Stefano Stabellini 2017-09-23 16:05 ` [Qemu-devel] xen/disk: don't leak stack data via response ring Michael Tokarev 2017-09-23 16:05 ` Michael Tokarev 2017-09-24 9:18 ` Michael Tokarev 2017-09-24 9:18 ` Michael Tokarev 2017-09-25 22:48 ` Stefano Stabellini 2017-09-25 22:48 ` Stefano Stabellini 2017-06-29 12:12 ` [Qemu-devel] [PATCH 0/3] please pull xen-20170627-tag Peter Maydell 2017-06-29 12:12 ` Peter Maydell
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