Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756806Ab0KPSci (ORCPT ); Tue, 16 Nov 2010 13:32:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:26401 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756749Ab0KPSch (ORCPT ); Tue, 16 Nov 2010 13:32:37 -0500 Subject: Re: [PATCH] vfio: fix config virtualization, esp command byte From: Alex Williamson To: Tom Lyon Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org In-Reply-To: <4cd9f0d6.jnHBr6PBphKwDwhM%pugs@cisco.com> References: <4cd9f0d6.jnHBr6PBphKwDwhM%pugs@cisco.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 16 Nov 2010 10:54:21 -0700 Message-ID: <1289930061.3069.5.camel@x201> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8370 Lines: 286 On Tue, 2010-11-09 at 17:09 -0800, Tom Lyon wrote: > Cleans up config space virtualization, especialy handling of bytes > which have some virtual and some real bits, like PCI_COMMAND. > > Alex, I hope you can test this with your setups. Sorry for the delay. FWIW, I'm not having much luck with this, I'll try to debug the problem. Thanks, Alex > Signed-off-by: Tom Lyon > --- > drivers/vfio/vfio_pci_config.c | 166 +++++++++++++--------------------------- > 1 files changed, 53 insertions(+), 113 deletions(-) > > diff --git a/drivers/vfio/vfio_pci_config.c b/drivers/vfio/vfio_pci_config.c > index 8304316..7132ac4 100644 > --- a/drivers/vfio/vfio_pci_config.c > +++ b/drivers/vfio/vfio_pci_config.c > @@ -745,6 +745,8 @@ static int vfio_virt_init(struct vfio_dev *vdev) > */ > static void vfio_bar_restore(struct vfio_dev *vdev) > { > + if (vdev->pdev->is_virtfn) > + return; > printk(KERN_WARNING "%s: reset recovery - restoring bars\n", __func__); > > #define do_bar(off, which) \ > @@ -815,26 +817,15 @@ static inline int vfio_read_config_byte(struct vfio_dev *vdev, > static inline int vfio_write_config_byte(struct vfio_dev *vdev, > int pos, u8 val) > { > - vdev->vconfig[pos] = val; > return pci_user_write_config_byte(vdev->pdev, pos, val); > } > > /* handle virtualized fields in the basic config space */ > -static u8 vfio_virt_basic(struct vfio_dev *vdev, int write, > - u16 pos, u16 off, u8 val, u8 newval) > +static void vfio_virt_basic(struct vfio_dev *vdev, int write, u16 pos, u8 *rbp) > { > - switch (off) { > - /* > - * vendor and device are virt because they don't > - * show up otherwise for sr-iov vfs > - */ > - case PCI_VENDOR_ID: > - case PCI_VENDOR_ID + 1: > - case PCI_DEVICE_ID: > - case PCI_DEVICE_ID + 1: > - /* read only */ > - val = vdev->vconfig[pos]; > - break; > + u8 val; > + > + switch (pos) { > case PCI_COMMAND: > /* > * If the real mem or IO enable bits are zero > @@ -842,100 +833,58 @@ static u8 vfio_virt_basic(struct vfio_dev *vdev, int write, > * Restore the real BARs before allowing those > * bits to re-enable > */ > + val = vdev->vconfig[pos]; > if (vdev->pdev->is_virtfn) > val |= PCI_COMMAND_MEMORY; > if (write) { > - int upd = 0; > - > - upd = (newval & PCI_COMMAND_MEMORY) > > - (val & PCI_COMMAND_MEMORY); > - upd += (newval & PCI_COMMAND_IO) > > - (val & PCI_COMMAND_IO); > - if (upd) > - vfio_bar_restore(vdev); > - vfio_write_config_byte(vdev, pos, newval); > - } > - break; > - case PCI_BASE_ADDRESS_0: > - case PCI_BASE_ADDRESS_0+1: > - case PCI_BASE_ADDRESS_0+2: > - case PCI_BASE_ADDRESS_0+3: > - case PCI_BASE_ADDRESS_1: > - case PCI_BASE_ADDRESS_1+1: > - case PCI_BASE_ADDRESS_1+2: > - case PCI_BASE_ADDRESS_1+3: > - case PCI_BASE_ADDRESS_2: > - case PCI_BASE_ADDRESS_2+1: > - case PCI_BASE_ADDRESS_2+2: > - case PCI_BASE_ADDRESS_2+3: > - case PCI_BASE_ADDRESS_3: > - case PCI_BASE_ADDRESS_3+1: > - case PCI_BASE_ADDRESS_3+2: > - case PCI_BASE_ADDRESS_3+3: > - case PCI_BASE_ADDRESS_4: > - case PCI_BASE_ADDRESS_4+1: > - case PCI_BASE_ADDRESS_4+2: > - case PCI_BASE_ADDRESS_4+3: > - case PCI_BASE_ADDRESS_5: > - case PCI_BASE_ADDRESS_5+1: > - case PCI_BASE_ADDRESS_5+2: > - case PCI_BASE_ADDRESS_5+3: > - case PCI_ROM_ADDRESS: > - case PCI_ROM_ADDRESS+1: > - case PCI_ROM_ADDRESS+2: > - case PCI_ROM_ADDRESS+3: > - if (write) { > - vdev->vconfig[pos] = newval; > - vdev->bardirty = 1; > - } else { > - if (vdev->bardirty) > - vfio_bar_fixup(vdev); > - val = vdev->vconfig[pos]; > + > + if (((val & PCI_COMMAND_MEMORY) > > + (*rbp & PCI_COMMAND_MEMORY)) || > + ((val & PCI_COMMAND_IO) > > + (*rbp & PCI_COMMAND_IO))) > + vfio_bar_restore(vdev); > + *rbp &= ~(PCI_COMMAND_MEMORY + PCI_COMMAND_IO); > + *rbp |= val & (PCI_COMMAND_MEMORY + PCI_COMMAND_IO); > } > + vdev->vconfig[pos] = val; > break; > - default: > + case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_5 + 3: > + case PCI_ROM_ADDRESS ... PCI_ROM_ADDRESS + 3: > if (write) > - vdev->vconfig[pos] = newval; > - else > - val = vdev->vconfig[pos]; > + vdev->bardirty = 1; > + else if (vdev->bardirty) > + vfio_bar_fixup(vdev); > break; > } > - return val; > } > > /* > * handle virtualized fields in msi capability > * easy, except for multiple-msi fields in flags byte > */ > -static u8 vfio_virt_msi(struct vfio_dev *vdev, int write, > - u16 pos, u16 off, u8 val, u8 newval) > +static void vfio_virt_msi(struct vfio_dev *vdev, int write, > + u16 pos, u16 off, u8 *rbp) > { > - if (off == PCI_MSI_FLAGS) { > - u8 num; > + u8 val; > + u8 num; > > + val = vdev->vconfig[pos]; > + if (off == PCI_MSI_FLAGS) { > if (write) { > if (!vdev->ev_msi) > - newval &= ~PCI_MSI_FLAGS_ENABLE; > - num = (newval & PCI_MSI_FLAGS_QSIZE) >> 4; > + val &= ~PCI_MSI_FLAGS_ENABLE; > + num = (val & PCI_MSI_FLAGS_QSIZE) >> 4; > if (num > vdev->msi_qmax) > num = vdev->msi_qmax; > - newval &= ~PCI_MSI_FLAGS_QSIZE; > - newval |= num << 4; > - vfio_write_config_byte(vdev, pos, newval); > + val &= ~PCI_MSI_FLAGS_QSIZE; > + val |= num << 4; > + *rbp = val; > } else { > - if (vfio_read_config_byte(vdev, pos, &val) < 0) > - return 0; > val &= ~PCI_MSI_FLAGS_QMASK; > val |= vdev->msi_qmax << 1; > } > - return val; > } > - > - if (write) > - vdev->vconfig[pos] = newval; > - else > - val = vdev->vconfig[pos]; > - return val; > + vdev->vconfig[pos] = val; > } > > static int vfio_config_rwbyte(int write, > @@ -950,6 +899,7 @@ static int vfio_config_rwbyte(int write, > struct perm_bits *perm; > u8 wr, virt; > int ret; > + u8 realbits = 0; > > cap = map[pos]; > if (cap == 0xFF) { /* unknown region */ > @@ -989,7 +939,7 @@ static int vfio_config_rwbyte(int write, > } > if (write && !wr) /* no writeable bits */ > return 0; > - if (!virt) { > + if (!virt) { /* no virtual bits */ > if (write) { > if (copy_from_user(&val, buf, 1)) > return -EFAULT; > @@ -1018,54 +968,44 @@ static int vfio_config_rwbyte(int write, > if (copy_from_user(&newval, buf, 1)) > return -EFAULT; > } > - /* > - * We get here if there are some virt bits > - * handle remaining real bits, if any > - */ > - if (~virt) { > - u8 rbits = (~virt) & wr; > > - ret = vfio_read_config_byte(vdev, pos, &val); > + if (~virt) { /* mix of real and virt bits */ > + /* update vconfig with latest hw bits */ > + ret = vfio_read_config_byte(vdev, pos, &realbits); > if (ret < 0) > return ret; > - if (write && rbits) { > - val &= ~rbits; > - val |= (newval & rbits); > - vfio_write_config_byte(vdev, pos, val); > - } > + vdev->vconfig[pos] = > + (vdev->vconfig[pos] & virt) | (realbits & ~virt); > } > + > + /* update vconfig with writeable bits */ > + vdev->vconfig[pos] = > + (vdev->vconfig[pos] & ~wr) | (newval & wr); > + > /* > - * Now handle entirely virtual fields > + * Now massage virtual fields > */ > if (pos < PCI_CFG_SPACE_SIZE) { > switch (cap) { > case PCI_CAP_ID_BASIC: /* virtualize BARs */ > - val = vfio_virt_basic(vdev, write, > - pos, off, val, newval); > + vfio_virt_basic(vdev, write, pos, &realbits); > break; > case PCI_CAP_ID_MSI: /* virtualize (parts of) MSI */ > - val = vfio_virt_msi(vdev, write, > - pos, off, val, newval); > - break; > - default: > - if (write) > - vdev->vconfig[pos] = newval; > - else > - val = vdev->vconfig[pos]; > + vfio_virt_msi(vdev, write, pos, off, &realbits); > break; > } > } else { > /* no virt fields yet in ecaps */ > switch (cap) { /* extended capabilities */ > default: > - if (write) > - vdev->vconfig[pos] = newval; > - else > - val = vdev->vconfig[pos]; > break; > } > } > - if (!write && copy_to_user(buf, &val, 1)) > + if (write && ~virt) { > + realbits = (realbits & virt) | (vdev->vconfig[pos] & ~virt); > + vfio_write_config_byte(vdev, pos, realbits); > + } > + if (!write && copy_to_user(buf, &vdev->vconfig[pos], 1)) > return -EFAULT; > return 0; > } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/