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Re: [Qemu-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize()
From: |
Stefano Stabellini |
Subject: |
Re: [Qemu-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize() |
Date: |
Thu, 7 Jan 2016 15:01:32 +0000 |
User-agent: |
Alpine 2.02 (DEB 1266 2009-07-14) |
Your patch is simpler and more mature. Maybe it should go in before Gerd's
series?
On Thu, 7 Jan 2016, Cao jin wrote:
> Hi
> Since Gerd has a whole patchset that covers this, Shall I continue with a
> new version of this?
>
> On 12/29/2015 07:25 PM, Michael S. Tsirkin wrote:
> > On Tue, Dec 29, 2015 at 04:46:03PM +0800, Cao jin wrote:
> > > Signed-off-by: Cao jin <address@hidden>
> > > ---
> > > changelog v4:
> > > 1. strip the bugfix code, but I guess this patch should be applied after
> > > that bugfix patch.
> > > 2. Other little fix as per previous review
> > >
> > > Some explanation to previous review:
> > > 1. error_setg_errno() I use in this patch will print the strerror(errno),
> > > so I
> > > guess it will be informative enough? example:
> > >
> > > error_setg_errno(errp, errno, "open %s fail", path); will print:
> > > "open bluhbluh fail: string_from_strerrer(errno)"
> >
> > I'd prefer some mention of why this is attempted too.
> > E.g. "igd passthrough : open bluhbluh fail"
> >
> > > 2. snprintf() has tiny tiny chance to fail,
> >
> > It just formats a string into a buffer. the buffer
> > is pre-allocated, and we know it's large enough for the data.
> > How can it fail?
> >
> >
> > > I don`t assert here, because this
> > > device is on-board, it init during machine initialization, in case it
> > > fails,
> > > the errp we set will results in error_report(err) and exit(1), at
> > > least can
> > > let user know why fail. see the call-chain:
> > >
> > > pc_xen_hvm_init_pci->pc_init1->i440fx_init->pci_create_simple->
> > > pci_create_simple_multifunction->qdev_init_nofail
> >
> > unlike open failing, there's nothing user can do, this means there's
> > a coding bug somewhere, and assert is easier to debug.
> >
> > > About test:
> > > 1. Compiled
> > > 2. Did a dirty hack to force create/realize this device in pc_init1(),
> > > prove
> > > that the realizing process is ok, I will reply this mail later to
> > > attch the
> > > screenshot evidence
> >
> > Good job, thanks!
> > You should also Cc Tiejun Chen <address@hidden> who wrote this
> > code, presumably with access to hardware to test on.
> >
> >
> > > hw/pci-host/piix.c | 30 +++++++++++++++---------------
> > > 1 file changed, 15 insertions(+), 15 deletions(-)
> > >
> > > diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
> > > index a9cb983..e91570f 100644
> > > --- a/hw/pci-host/piix.c
> > > +++ b/hw/pci-host/piix.c
> > > @@ -761,7 +761,7 @@ static const IGDHostInfo igd_host_bridge_infos[] = {
> > > {0xa8, 4}, /* SNB: base of GTT stolen memory */
> > > };
> > >
> > > -static int host_pci_config_read(int pos, int len, uint32_t *val)
> > > +static void host_pci_config_read(int pos, int len, uint32_t *val, Error
> > > **errp)
> > > {
> > > char path[PATH_MAX];
> > > int config_fd;
> > > @@ -769,19 +769,19 @@ static int host_pci_config_read(int pos, int len,
> > > uint32_t *val)
> > > /* Access real host bridge. */
> > > int rc = snprintf(path, size,
> > > "/sys/bus/pci/devices/%04x:%02x:%02x.%d/%s",
> > > 0, 0, 0, 0, "config");
> > > - int ret = 0;
> > >
> > > if (rc >= size || rc < 0) {
> > > - return -ENODEV;
> > > + error_setg_errno(errp, errno, "snprintf err");
> > > }
> > >
> > > config_fd = open(path, O_RDWR);
> > > if (config_fd < 0) {
> > > - return -ENODEV;
> > > + error_setg_errno(errp, errno, "open %s fail", path);
> > > + return;
> > > }
> > >
> > > if (lseek(config_fd, pos, SEEK_SET) != pos) {
> > > - ret = -errno;
> > > + error_setg_errno(errp, errno, "lseek err");
> > > goto out;
> > > }
> > >
> > > @@ -789,32 +789,32 @@ static int host_pci_config_read(int pos, int len,
> > > uint32_t *val)
> > > rc = read(config_fd, (uint8_t *)val, len);
> > > } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
> > > if (rc != len) {
> > > - ret = -errno;
> > > + error_setg_errno(errp, errno, "read err");
> > > }
> > >
> > > out:
> > > close(config_fd);
> > > - return ret;
> > > }
> > >
> > > -static int igd_pt_i440fx_initfn(struct PCIDevice *pci_dev)
> > > +static void igd_pt_i440fx_realize(struct PCIDevice *pci_dev, Error
> > > **errp)
> > > {
> > > uint32_t val = 0;
> > > - int rc, i, num;
> > > + int i, num;
> > > int pos, len;
> > > + Error *local_err = NULL;
> > >
> > > num = ARRAY_SIZE(igd_host_bridge_infos);
> > > for (i = 0; i < num; i++) {
> > > pos = igd_host_bridge_infos[i].offset;
> > > len = igd_host_bridge_infos[i].len;
> > > - rc = host_pci_config_read(pos, len, &val);
> > > - if (rc) {
> > > - return -ENODEV;
> > > +
> > > + host_pci_config_read(pos, len, &val, &local_err);
> > > + if (local_err) {
> > > + error_propagate(errp, local_err);
> > > + return;
> > > }
> > > pci_default_write_config(pci_dev, pos, cpu_to_le32(val), len);
> > > }
> > > -
> > > - return 0;
> > > }
> > >
> > > static void igd_passthrough_i440fx_class_init(ObjectClass *klass, void
> > > *data)
> > > @@ -822,7 +822,7 @@ static void
> > > igd_passthrough_i440fx_class_init(ObjectClass *klass, void *data)
> > > DeviceClass *dc = DEVICE_CLASS(klass);
> > > PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> > >
> > > - k->init = igd_pt_i440fx_initfn;
> > > + k->realize = igd_pt_i440fx_realize;
> > > dc->desc = "IGD Passthrough Host bridge";
> > > }
> > >
> > > --
> > > 2.1.0
> > >
> > >
> >
> >
> > .
> >
>
> --
> Yours Sincerely,
>
> Cao jin
>
>
>
- Re: [Qemu-devel] [Xen-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize(), (continued)
- Re: [Qemu-devel] [Xen-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize(), Hao, Xudong, 2016/01/07
- Re: [Qemu-devel] [Xen-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize(), Stefano Stabellini, 2016/01/08
- Re: [Qemu-devel] [Xen-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize(), Hao, Xudong, 2016/01/10
- Re: [Qemu-devel] [Xen-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize(), Hao, Xudong, 2016/01/11
- Re: [Qemu-devel] [Xen-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize(), Gerd Hoffmann, 2016/01/11
- Re: [Qemu-devel] [Xen-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize(), Stefano Stabellini, 2016/01/11
- Re: [Qemu-devel] [Xen-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize(), Michael S. Tsirkin, 2016/01/11
- Re: [Qemu-devel] [Xen-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize(), Cao jin, 2016/01/11
- Re: [Qemu-devel] [Xen-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize(), Hao, Xudong, 2016/01/11
Re: [Qemu-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize(), Cao jin, 2016/01/07
- Re: [Qemu-devel] [PATCH v4] igd-passthrough-i440FX: convert to realize(),
Stefano Stabellini <=