From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH v3 for 4.5] ioreq-server: handle the lack of a default emulator properly Date: Tue, 30 Sep 2014 10:31:16 +0100 Message-ID: <542A7864.6040807@citrix.com> References: <1412068735-10840-1-git-send-email-paul.durrant@citrix.com> <542A77E1.3050705@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <542A77E1.3050705@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Paul Durrant , xen-devel@lists.xen.org Cc: Keir Fraser , Jan Beulich List-Id: xen-devel@lists.xenproject.org On 30/09/14 10:29, Andrew Cooper wrote: > On 30/09/14 10:18, Paul Durrant wrote: >> I started porting QEMU over to use the new ioreq server API and hit a >> problem with PCI bus enumeration. Because, with my patches, QEMU only >> registers to handle config space accesses for the PCI device it implements >> all other attempts by the guest to access 0xcfc go nowhere and this was >> causing the vcpu to wedge up because nothing was completing the I/O. >> >> This patch introduces an I/O completion handler into the hypervisor for the >> case where no ioreq server matches a particular request. Read requests are >> completed with 0xf's in the data buffer, writes and all other I/O req types >> are ignored. >> >> Signed-off-by: Paul Durrant >> Cc: Keir Fraser >> Cc: Jan Beulich > One bug, couple of nits. > > It is probably worth having a sentence in the commit message concerning > the removal of list_is_singular(). > >> --- >> v3: - Fix for backwards string instruction emulation >> >> v2: - First non-RFC submission >> - Removed warning on unemulated MMIO accesses >> >> xen/arch/x86/hvm/hvm.c | 35 ++++++++++++++++++++++++++++++++--- >> 1 file changed, 32 insertions(+), 3 deletions(-) >> >> diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c >> index 5c7e0a4..e6611ed 100644 >> --- a/xen/arch/x86/hvm/hvm.c >> +++ b/xen/arch/x86/hvm/hvm.c >> @@ -2386,8 +2386,7 @@ static struct hvm_ioreq_server *hvm_select_ioreq_server(struct domain *d, >> if ( list_empty(&d->arch.hvm_domain.ioreq_server.list) ) >> return NULL; >> >> - if ( list_is_singular(&d->arch.hvm_domain.ioreq_server.list) || >> - (p->type != IOREQ_TYPE_COPY && p->type != IOREQ_TYPE_PIO) ) >> + if ( p->type != IOREQ_TYPE_COPY && p->type != IOREQ_TYPE_PIO ) >> return d->arch.hvm_domain.default_ioreq_server; >> >> cf8 = d->arch.hvm_domain.pci_cf8; >> @@ -2618,12 +2617,42 @@ bool_t hvm_send_assist_req_to_ioreq_server(struct hvm_ioreq_server *s, >> return 0; >> } >> >> +static bool_t hvm_complete_assist_req(ioreq_t *p) >> +{ >> + switch (p->type) > Style: ( p-> type ) Hmm - I am not sure where the space following -> appeared from, but I meant "( p->type )". Apologies. ~Andrew