From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52641) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aKnI4-0007Nn-2a for qemu-devel@nongnu.org; Sun, 17 Jan 2016 08:22:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aKnI0-00036I-SX for qemu-devel@nongnu.org; Sun, 17 Jan 2016 08:22:44 -0500 Received: from mail-wm0-x242.google.com ([2a00:1450:400c:c09::242]:33366) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aKnI0-00036D-Ij for qemu-devel@nongnu.org; Sun, 17 Jan 2016 08:22:40 -0500 Received: by mail-wm0-x242.google.com with SMTP id u188so11527572wmu.0 for ; Sun, 17 Jan 2016 05:22:40 -0800 (PST) References: <093036e6a4398c01ba4ead12cd064932087e3da7.1452564770.git.chen.fan.fnst@cn.fujitsu.com> From: Marcel Apfelbaum Message-ID: <569B959D.9080206@gmail.com> Date: Sun, 17 Jan 2016 15:22:37 +0200 MIME-Version: 1.0 In-Reply-To: <093036e6a4398c01ba4ead12cd064932087e3da7.1452564770.git.chen.fan.fnst@cn.fujitsu.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v16 05/14] vfio: add pcie extanded capability support Reply-To: marcel@redhat.com List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Cao jin , qemu-devel@nongnu.org Cc: chen.fan.fnst@cn.fujitsu.com, izumi.taku@jp.fujitsu.com, alex.williamson@redhat.com, mst@redhat.com On 01/12/2016 04:43 AM, Cao jin wrote: > From: Chen Fan > Hi, I noticed a type in the subject, extanded -> extended > For vfio pcie device, we could expose the extended capability on > PCIE bus. in order to avoid config space broken, we introduce > a copy config for parsing extended caps. and rebuild the pcie > extended config space. Maybe we can re-word this. Will someone with better English skills advice :) ? > > Signed-off-by: Chen Fan > --- > hw/vfio/pci.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 69 insertions(+), 1 deletion(-) > > diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c > index 288f2c7..64b0867 100644 > --- a/hw/vfio/pci.c > +++ b/hw/vfio/pci.c > @@ -1482,6 +1482,21 @@ static uint8_t vfio_std_cap_max_size(PCIDevice *pdev, uint8_t pos) > return next - pos; > } > > + > +static uint16_t vfio_ext_cap_max_size(const uint8_t *config, uint16_t pos) > +{ > + uint16_t tmp, next = PCIE_CONFIG_SPACE_SIZE; > + > + for (tmp = PCI_CONFIG_SPACE_SIZE; tmp; > + tmp = PCI_EXT_CAP_NEXT(pci_get_long(config + tmp))) { > + if (tmp > pos && tmp < next) { > + next = tmp; > + } > + } > + > + return next - pos; > +} Can't we reuse vfio_std_cap_max_size here? if only the config size differs, we can pass it as parameter. > + > static void vfio_set_word_bits(uint8_t *buf, uint16_t val, uint16_t mask) > { > pci_set_word(buf, (pci_get_word(buf) & ~mask) | val); > @@ -1817,16 +1832,69 @@ static int vfio_add_std_cap(VFIOPCIDevice *vdev, uint8_t pos) > return 0; > } > > +static int vfio_add_ext_cap(VFIOPCIDevice *vdev) > +{ > + PCIDevice *pdev = &vdev->pdev; > + uint32_t header; > + uint16_t cap_id, next, size; > + uint8_t cap_ver; > + uint8_t *config; > + > + /* > + * In order to avoid breaking config space, create a copy to > + * use for parsing extended capabilities. It will be nice to know *how* do we break/*what* will break the config space, I confess that I didn't see it :(. > + */ > + config = g_memdup(pdev->config, vdev->config_size); > + > + for (next = PCI_CONFIG_SPACE_SIZE; next; > + next = PCI_EXT_CAP_NEXT(pci_get_long(config + next))) { > + header = pci_get_long(config + next); > + cap_id = PCI_EXT_CAP_ID(header); > + cap_ver = PCI_EXT_CAP_VER(header); > + > + /* > + * If it becomes important to configure extended capabilities to their > + * actual size, use this as the default when it's something we don't > + * recognize. Since QEMU doesn't actually handle many of the config > + * accesses, exact size doesn't seem worthwhile. > + */ > + size = vfio_ext_cap_max_size(config, next); > + > + pcie_add_capability(pdev, cap_id, cap_ver, next, size); > + pci_set_long(dev->config + next, PCI_EXT_CAP(cap_id, cap_ver, 0)); > + > + /* Use emulated next pointer to allow dropping extended caps */ > + pci_long_test_and_set_mask(vdev->emulated_config_bits + next, > + PCI_EXT_CAP_NEXT_MASK); > + } > + > + g_free(config); > + return 0; > +} > + > static int vfio_add_capabilities(VFIOPCIDevice *vdev) > { > PCIDevice *pdev = &vdev->pdev; > + int ret; > > if (!(pdev->config[PCI_STATUS] & PCI_STATUS_CAP_LIST) || > !pdev->config[PCI_CAPABILITY_LIST]) { > return 0; /* Nothing to add */ > } > > - return vfio_add_std_cap(vdev, pdev->config[PCI_CAPABILITY_LIST]); > + ret = vfio_add_std_cap(vdev, pdev->config[PCI_CAPABILITY_LIST]); > + if (ret) { > + return ret; > + } > + > + /* on PCI bus, it doesn't make sense to expose extended capabilities. */ > + if (!pci_is_express(pdev) || > + !pci_bus_is_express(pdev->bus) || > + !pci_get_long(pdev->config + PCI_CONFIG_SPACE_SIZE)) { I am curious about the last check, "!pci_get_long(pdev->config + PCI_CONFIG_SPACE_SIZE)", can you please explain? Thank you, Marcel > + return 0; > + } > + > + return vfio_add_ext_cap(vdev); > } > > static void vfio_pci_pre_reset(VFIOPCIDevice *vdev) >