From 84237a826b261de7ddd3d09ee53ee68cb4138937 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Mon, 18 Feb 2013 10:11:13 -0700 Subject: [PATCH] vfio-pci: Add support for VGA region access PCI defines display class VGA regions at I/O port address 0x3b0, 0x3c0 and MMIO address 0xa0000. As these are non-overlapping, we can ignore the I/O port vs MMIO difference and expose them both in a single region. We make use of the VGA arbiter around each access to configure chipset access as necessary. Signed-off-by: Alex Williamson --- drivers/vfio/pci/Kconfig | 10 +++++ drivers/vfio/pci/vfio_pci.c | 18 +++++++++ drivers/vfio/pci/vfio_pci_private.h | 4 ++ drivers/vfio/pci/vfio_pci_rdwr.c | 61 +++++++++++++++++++++++++++++ include/uapi/linux/vfio.h | 9 +++++ 5 files changed, 102 insertions(+) diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig index 5980758563eb..e84300b268b6 100644 --- a/drivers/vfio/pci/Kconfig +++ b/drivers/vfio/pci/Kconfig @@ -6,3 +6,13 @@ config VFIO_PCI use of PCI drivers using the VFIO framework. If you don't know what to do here, say N. + +config VFIO_PCI_VGA + bool "VFIO PCI support for VGA devices" + depends on VFIO_PCI && X86 && VGA_ARB && EXPERIMENTAL + help + Support for VGA extension to VFIO PCI. This exposes an additional + region on VGA devices for accessing legacy VGA addresses used by + BIOS and generic video drivers. + + If you don't know what to do here, say N. diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index bb8c8c2be960..8189cb6a86af 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -84,6 +84,11 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev) } else vdev->msix_bar = 0xFF; +#ifdef CONFIG_VFIO_PCI_VGA + if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA) + vdev->has_vga = true; +#endif + return 0; } @@ -285,6 +290,16 @@ static long vfio_pci_ioctl(void *device_data, info.flags = VFIO_REGION_INFO_FLAG_READ; break; } + case VFIO_PCI_VGA_REGION_INDEX: + if (!vdev->has_vga) + return -EINVAL; + + info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index); + info.size = 0xc0000; + info.flags = VFIO_REGION_INFO_FLAG_READ | + VFIO_REGION_INFO_FLAG_WRITE; + + break; default: return -EINVAL; } @@ -386,6 +401,9 @@ static ssize_t vfio_pci_rw(void *device_data, char __user *buf, case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX: return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite); + + case VFIO_PCI_VGA_REGION_INDEX: + return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite); } return -EINVAL; diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h index 00d19b953ce4..d7e55d03f49e 100644 --- a/drivers/vfio/pci/vfio_pci_private.h +++ b/drivers/vfio/pci/vfio_pci_private.h @@ -53,6 +53,7 @@ struct vfio_pci_device { bool reset_works; bool extended_caps; bool bardirty; + bool has_vga; struct pci_saved_state *pci_saved_state; atomic_t refcnt; }; @@ -77,6 +78,9 @@ extern ssize_t vfio_pci_config_rw(struct vfio_pci_device *vdev, extern ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf, size_t count, loff_t *ppos, bool iswrite); +extern ssize_t vfio_pci_vga_rw(struct vfio_pci_device *vdev, char __user *buf, + size_t count, loff_t *ppos, bool iswrite); + extern int vfio_pci_init_perm_bits(void); extern void vfio_pci_uninit_perm_bits(void); diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c index e9d78eb91ed7..210db24d2204 100644 --- a/drivers/vfio/pci/vfio_pci_rdwr.c +++ b/drivers/vfio/pci/vfio_pci_rdwr.c @@ -17,6 +17,7 @@ #include #include #include +#include #include "vfio_pci_private.h" @@ -175,3 +176,63 @@ ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf, return done; } + +ssize_t vfio_pci_vga_rw(struct vfio_pci_device *vdev, char __user *buf, + size_t count, loff_t *ppos, bool iswrite) +{ + int ret; + loff_t off, pos = *ppos & VFIO_PCI_OFFSET_MASK; + void __iomem *iomem = NULL; + unsigned int rsrc; + bool is_ioport; + ssize_t done; + + if (!vdev->has_vga) + return -EINVAL; + + switch (pos) { + case 0xa0000 ... 0xbffff: + count = min(count, (size_t)(0xc0000 - pos)); + iomem = ioremap_nocache(0xa0000, 0xbffff - 0xa0000 + 1); + off = pos - 0xa0000; + rsrc = VGA_RSRC_LEGACY_MEM; + is_ioport = false; + break; + case 0x3b0 ... 0x3bb: + count = min(count, (size_t)(0x3bc - pos)); + iomem = ioport_map(0x3b0, 0x3bb - 0x3b0 + 1); + off = pos - 0x3b0; + rsrc = VGA_RSRC_LEGACY_IO; + is_ioport = true; + break; + case 0x3c0 ... 0x3df: + count = min(count, (size_t)(0x3e0 - pos)); + iomem = ioport_map(0x3c0, 0x3df - 0x3c0 + 1); + off = pos - 0x3c0; + rsrc = VGA_RSRC_LEGACY_IO; + is_ioport = true; + break; + default: + return -EINVAL; + } + + if (!iomem) + return -ENOMEM; + + ret = vga_get_interruptible(vdev->pdev, rsrc); + if (ret) { + is_ioport ? ioport_unmap(iomem) : iounmap(iomem); + return ret; + } + + done = do_io_rw(iomem, buf, off, count, 0, 0, iswrite); + + vga_put(vdev->pdev, rsrc); + + is_ioport ? ioport_unmap(iomem) : iounmap(iomem); + + if (done >= 0) + *ppos += done; + + return done; +} diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 4758d1bfcf41..4f41f309911e 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -303,6 +303,15 @@ enum { VFIO_PCI_BAR5_REGION_INDEX, VFIO_PCI_ROM_REGION_INDEX, VFIO_PCI_CONFIG_REGION_INDEX, + /* + * Expose VGA regions defined for PCI base class 03, subclass 00. + * This includes I/O port ranges 0x3b0 to 0x3bb and 0x3c0 to 0x3df + * as well as the MMIO range 0xa0000 to 0xbffff. Each implemented + * range is found at it's identity mapped offset from the region + * offset, for example 0x3b0 is region_info.offset + 0x3b0. Areas + * between described ranges are unimplemented. + */ + VFIO_PCI_VGA_REGION_INDEX, VFIO_PCI_NUM_REGIONS };