From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49670) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WYdrw-0000ya-0B for qemu-devel@nongnu.org; Fri, 11 Apr 2014 12:00:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WYdrq-0001mp-SA for qemu-devel@nongnu.org; Fri, 11 Apr 2014 11:59:55 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:52321) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WYdrq-0001mg-MG for qemu-devel@nongnu.org; Fri, 11 Apr 2014 11:59:50 -0400 Date: Fri, 11 Apr 2014 10:59:45 -0500 From: Serge Hallyn Message-ID: <20140411155945.GA27476@sergelap> References: <1397205095-29830-1-git-send-email-mjt@msgid.tls.msk.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1397205095-29830-1-git-send-email-mjt@msgid.tls.msk.ru> Subject: Re: [Qemu-devel] [PATCH for-2.0] kvm_physical_sync_dirty_bitmap: ignore ENOENT from kvm_vm_ioctl List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Michael Tokarev Cc: Peter Maydell , qemu-devel@nongnu.org, Mario Smarduch Quoting Michael Tokarev (mjt@tls.msk.ru): > ENOENT means the kernel has an empty dirty bitmap for this > slot. Don't abort in that case. This appears to solve > the bug reported at > > https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1303926 > > which first showed up with commit b533f658a98325d: fix return > check for KVM_GET_DIRTY_LOG ioctl > > Cc: Serge Hallyn > Signed-off-by: Michael Tokarev This does look better than my version, thanks. As you say my version was closer to the old behavior, but if the kernel has no dirty bitmap we shouldn't be acting on it, so this looks better imo. Acked-by: Serge E. Hallyn (I've not tested yet, but it looks right and works for you :) > --- > kvm-all.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/kvm-all.c b/kvm-all.c > index cd4111d..47fa948 100644 > --- a/kvm-all.c > +++ b/kvm-all.c > @@ -441,13 +441,19 @@ static int kvm_physical_sync_dirty_bitmap(MemoryRegionSection *section) > > d.slot = mem->slot; > > - if (kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) < 0) { > + ret = kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d); > + if (ret >= 0) { > + /* regular case, process returned bitmap */ > + kvm_get_dirty_pages_log_range(section, d.dirty_bitmap); > + } else if (ret == -ENOENT) { > + /* kernel does not have dirty bitmap in this slot */ > + ret = 0; > + } else { > DPRINTF("ioctl failed %d\n", errno); > ret = -1; > break; > } > > - kvm_get_dirty_pages_log_range(section, d.dirty_bitmap); > start_addr = mem->start_addr + mem->memory_size; > } > g_free(d.dirty_bitmap); > -- > 1.7.10.4 >