From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org
Subject: [PULL 26/26] scsi-generic: pass max_segments via max_iov field in BlockLimits
Date: Thu, 20 May 2021 10:22:57 +0200 [thread overview]
Message-ID: <20210520082257.187061-27-pbonzini@redhat.com> (raw)
In-Reply-To: <20210520082257.187061-1-pbonzini@redhat.com>
I/O to a disk via read/write is not limited by the number of segments allowed
by the host adapter; the kernel can split requests if needed, and the limit
imposed by the host adapter can be very low (256k or so) to avoid that SG_IO
returns EINVAL if memory is heavily fragmented.
Since this value is only interesting for SG_IO-based I/O, do not include
it in the max_transfer and only take it into account when patching the
block limits VPD page in the scsi-generic device.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
block/file-posix.c | 3 +--
hw/scsi/scsi-generic.c | 6 ++++--
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/block/file-posix.c b/block/file-posix.c
index 10b71d9a13..59c889d5a7 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1228,8 +1228,7 @@ static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
ret = sg_get_max_segments(s->fd);
if (ret > 0) {
- bs->bl.max_transfer = MIN(bs->bl.max_transfer,
- ret * qemu_real_host_page_size);
+ bs->bl.max_iov = ret;
}
}
diff --git a/hw/scsi/scsi-generic.c b/hw/scsi/scsi-generic.c
index 98c30c5d5c..82e1e2ee79 100644
--- a/hw/scsi/scsi-generic.c
+++ b/hw/scsi/scsi-generic.c
@@ -179,10 +179,12 @@ static void scsi_handle_inquiry_reply(SCSIGenericReq *r, SCSIDevice *s)
(r->req.cmd.buf[1] & 0x01)) {
page = r->req.cmd.buf[2];
if (page == 0xb0) {
- uint32_t max_transfer =
- blk_get_max_transfer(s->conf.blk) / s->blocksize;
+ uint32_t max_transfer = blk_get_max_transfer(s->conf.blk);
+ uint32_t max_iov = blk_get_max_iov(s->conf.blk);
assert(max_transfer);
+ max_transfer = MIN_NON_ZERO(max_transfer, max_iov * qemu_real_host_page_size)
+ / s->blocksize;
stl_be_p(&r->buf[8], max_transfer);
/* Also take care of the opt xfer len. */
stl_be_p(&r->buf[12],
--
2.31.1
next prev parent reply other threads:[~2021-05-20 8:40 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-20 8:22 [PULL 00/26] Misc patches for 2021-05-20 Paolo Bonzini
2021-05-20 8:22 ` [PULL 01/26] configure: Only clone softfloat-3 repositories if TCG is enabled Paolo Bonzini
2021-05-20 8:22 ` [PULL 02/26] configure: check for submodules if --with-git-submodules=ignore Paolo Bonzini
2021-05-20 8:22 ` [PULL 03/26] configure: simplify assignment to GIT_SUBMODULES Paolo Bonzini
2021-05-20 8:22 ` [PULL 04/26] hw/mem/nvdimm: Use Kconfig 'imply' instead of 'depends on' Paolo Bonzini
2021-05-20 8:22 ` [PULL 05/26] i386/cpu: Expose AVX_VNNI instruction to guest Paolo Bonzini
2021-05-20 8:22 ` [PULL 06/26] meson: bump submodule to 0.57.2 Paolo Bonzini
2021-05-20 8:22 ` [PULL 07/26] object: add more commands to preconfig mode Paolo Bonzini
2021-05-20 8:22 ` [PULL 08/26] qtest: add a QOM object for qtest Paolo Bonzini
2021-05-20 8:22 ` [PULL 09/26] KVM: do not allow setting properties at runtime Paolo Bonzini
2021-05-20 8:22 ` [PULL 10/26] memory: Introduce log_sync_global() to memory listener Paolo Bonzini
2021-05-20 8:22 ` [PULL 11/26] KVM: Use a big lock to replace per-kml slots_lock Paolo Bonzini
2021-05-20 8:22 ` [PULL 12/26] KVM: Create the KVMSlot dirty bitmap on flag changes Paolo Bonzini
2021-05-20 8:22 ` [PULL 13/26] KVM: Provide helper to get kvm dirty log Paolo Bonzini
2021-05-20 8:22 ` [PULL 14/26] KVM: Provide helper to sync dirty bitmap from slot to ramblock Paolo Bonzini
2021-05-20 8:22 ` [PULL 15/26] KVM: Simplify dirty log sync in kvm_set_phys_mem Paolo Bonzini
2021-05-20 8:22 ` [PULL 16/26] KVM: Cache kvm slot dirty bitmap size Paolo Bonzini
2021-05-20 8:22 ` [PULL 17/26] KVM: Add dirty-ring-size property Paolo Bonzini
2021-05-20 8:22 ` [PULL 18/26] KVM: Disable manual dirty log when dirty ring enabled Paolo Bonzini
2021-05-20 8:22 ` [PULL 19/26] KVM: Dirty ring support Paolo Bonzini
2021-05-20 8:22 ` [PULL 20/26] tests/qtest/fuzz: Fix build failure Paolo Bonzini
2021-05-20 8:22 ` [PULL 21/26] meson: Set implicit_include_directories to false Paolo Bonzini
2021-05-20 8:22 ` [PULL 22/26] remove qemu-options* from root directory Paolo Bonzini
2021-05-20 8:22 ` [PULL 23/26] replication: move include out of " Paolo Bonzini
2021-05-20 8:22 ` [PULL 24/26] vl: allow not specifying size in -m when using -M memory-backend Paolo Bonzini
2021-05-20 8:22 ` [PULL 25/26] qemu-config: load modules when instantiating option groups Paolo Bonzini
2021-05-20 8:22 ` Paolo Bonzini [this message]
2021-05-20 8:54 ` [PULL 00/26] Misc patches for 2021-05-20 no-reply
2021-05-20 13:26 ` Peter Maydell
2021-05-20 14:20 ` Peter Maydell
2021-05-20 14:25 ` Peter Maydell
2021-05-21 13:27 ` Paolo Bonzini
2021-05-21 13:44 ` Peter Maydell
2021-05-24 9:42 ` Paolo Bonzini
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210520082257.187061-27-pbonzini@redhat.com \
--to=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).