* [PATCH 0/1] vfio-pci: Towards VGA support
@ 2013-01-07 22:07 Alex Williamson
2013-01-07 22:07 ` [PATCH] vfio-pci: [NOT FOR COMMIT] Add support for legacy MMIO & I/O port towards " Alex Williamson
0 siblings, 1 reply; 2+ messages in thread
From: Alex Williamson @ 2013-01-07 22:07 UTC (permalink / raw)
To: alex.williamson, kvm; +Cc: linux-kernel
vfio makes a nice interface to start looking at supporting VGA devices
assigned to virtual machines (ie. userspace drivers) because we can so
easily add additional ranges for a device. In this patch we add
legacy MMIO (below 1MB) and I/O port (64k) to devices with PCI class
code VGA. We can then use the kernel VGA arbiter service to change
chipset routing for each access to the VGA ranges defined in the PCI
spec. The rest of the region space not used by VGA is left
inaccessible until we add future feature that needs some other
legacy range.
There's also a qemu userspace companion series to this which learns
how to look for this new feature flag and setup ranges. Together
they get a step closer to supporting vfio-based VGA assignment, but
it doesn't yet work. I'm posting in this broken state both for
archival purposes as well as the hope that someone has ideas of what
might be missing or be able to pick up and run with this code.
Some cards are able to get through execution of their VGA BIOS with
these patches, but none that I've seen sync the monitor to VGA text
mode from seabios. With a hack in qemu for a card specific backdoor
on a Radeon HD5450 I've been able to get syslinux graphics mode to
work and Windows will use it during normal bootup. I have no idea
what might be missing for VGA text mode. Thanks,
Alex
---
Alex Williamson (1):
vfio-pci: [NOT FOR COMMIT] Add support for legacy MMIO & I/O port towards VGA support
drivers/vfio/pci/vfio_pci.c | 74 ++++++++++++---
drivers/vfio/pci/vfio_pci_private.h | 6 +
drivers/vfio/pci/vfio_pci_rdwr.c | 170 +++++++++++++++++++++++++++--------
include/uapi/linux/vfio.h | 3 +
4 files changed, 197 insertions(+), 56 deletions(-)
^ permalink raw reply [flat|nested] 2+ messages in thread
* [PATCH] vfio-pci: [NOT FOR COMMIT] Add support for legacy MMIO & I/O port towards VGA support
2013-01-07 22:07 [PATCH 0/1] vfio-pci: Towards VGA support Alex Williamson
@ 2013-01-07 22:07 ` Alex Williamson
0 siblings, 0 replies; 2+ messages in thread
From: Alex Williamson @ 2013-01-07 22:07 UTC (permalink / raw)
To: alex.williamson, kvm; +Cc: linux-kernel
Create two new legacy regions, one for MMIO space below 1MB and
another for 64k of I/O port space. For devices of PCI class VGA
these ranges will be exposed and allow direct access to the device
at the PCI defined VGA addresses, 0xa0000, 0x3b0, 0x3c0. VFIO
makes use of the host VGA arbiter to manage host chipset config
to route each access to the correct device.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
drivers/vfio/pci/vfio_pci.c | 74 ++++++++++++---
drivers/vfio/pci/vfio_pci_private.h | 6 +
drivers/vfio/pci/vfio_pci_rdwr.c | 170 +++++++++++++++++++++++++++--------
include/uapi/linux/vfio.h | 3 +
4 files changed, 197 insertions(+), 56 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index b28e66c..8a09c33 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -223,9 +223,14 @@ static long vfio_pci_ioctl(void *device_data,
if (vdev->reset_works)
info.flags |= VFIO_DEVICE_FLAGS_RESET;
- info.num_regions = VFIO_PCI_NUM_REGIONS;
+ info.num_regions = VFIO_PCI_CONFIG_REGION_INDEX + 1;
info.num_irqs = VFIO_PCI_NUM_IRQS;
+ if ((vdev->pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA) {
+ info.flags |= VFIO_DEVICE_FLAGS_VGA;
+ info.num_regions += 2;
+ }
+
return copy_to_user((void __user *)arg, &info, minsz);
} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
@@ -285,6 +290,26 @@ static long vfio_pci_ioctl(void *device_data,
info.flags = VFIO_REGION_INFO_FLAG_READ;
break;
}
+ case VFIO_PCI_LEGACY_MMIO_REGION_INDEX:
+ if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
+ return -EINVAL;
+
+ info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
+ info.size = 1024 * 1024;
+ info.flags = VFIO_REGION_INFO_FLAG_READ |
+ VFIO_REGION_INFO_FLAG_WRITE;
+
+ break;
+ case VFIO_PCI_LEGACY_IOPORT_REGION_INDEX:
+ if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
+ return -EINVAL;
+
+ info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
+ info.size = 64 * 1024;
+ info.flags = VFIO_REGION_INFO_FLAG_READ |
+ VFIO_REGION_INFO_FLAG_WRITE;
+
+ break;
default:
return -EINVAL;
}
@@ -376,14 +401,25 @@ static ssize_t vfio_pci_read(void *device_data, char __user *buf,
if (index >= VFIO_PCI_NUM_REGIONS)
return -EINVAL;
- if (index == VFIO_PCI_CONFIG_REGION_INDEX)
+ switch (index) {
+ case VFIO_PCI_CONFIG_REGION_INDEX:
return vfio_pci_config_readwrite(vdev, buf, count, ppos, false);
- else if (index == VFIO_PCI_ROM_REGION_INDEX)
- return vfio_pci_mem_readwrite(vdev, buf, count, ppos, false);
- else if (pci_resource_flags(pdev, index) & IORESOURCE_IO)
- return vfio_pci_io_readwrite(vdev, buf, count, ppos, false);
- else if (pci_resource_flags(pdev, index) & IORESOURCE_MEM)
+ case VFIO_PCI_ROM_REGION_INDEX:
return vfio_pci_mem_readwrite(vdev, buf, count, ppos, false);
+ case VFIO_PCI_LEGACY_MMIO_REGION_INDEX:
+ return vfio_pci_legacy_mem_readwrite(vdev, buf, count,
+ ppos, false);
+ case VFIO_PCI_LEGACY_IOPORT_REGION_INDEX:
+ return vfio_pci_legacy_io_readwrite(vdev, buf, count,
+ ppos, false);
+ default:
+ if (pci_resource_flags(pdev, index) & IORESOURCE_IO)
+ return vfio_pci_io_readwrite(vdev, buf, count,
+ ppos, false);
+ if (pci_resource_flags(pdev, index) & IORESOURCE_MEM)
+ return vfio_pci_mem_readwrite(vdev, buf, count,
+ ppos, false);
+ }
return -EINVAL;
}
@@ -398,17 +434,25 @@ static ssize_t vfio_pci_write(void *device_data, const char __user *buf,
if (index >= VFIO_PCI_NUM_REGIONS)
return -EINVAL;
- if (index == VFIO_PCI_CONFIG_REGION_INDEX)
+ switch (index) {
+ case VFIO_PCI_CONFIG_REGION_INDEX:
return vfio_pci_config_readwrite(vdev, (char __user *)buf,
count, ppos, true);
- else if (index == VFIO_PCI_ROM_REGION_INDEX)
+ case VFIO_PCI_ROM_REGION_INDEX:
return -EINVAL;
- else if (pci_resource_flags(pdev, index) & IORESOURCE_IO)
- return vfio_pci_io_readwrite(vdev, (char __user *)buf,
- count, ppos, true);
- else if (pci_resource_flags(pdev, index) & IORESOURCE_MEM) {
- return vfio_pci_mem_readwrite(vdev, (char __user *)buf,
- count, ppos, true);
+ case VFIO_PCI_LEGACY_MMIO_REGION_INDEX:
+ return vfio_pci_legacy_mem_readwrite(vdev, buf, count,
+ ppos, false);
+ case VFIO_PCI_LEGACY_IOPORT_REGION_INDEX:
+ return vfio_pci_legacy_io_readwrite(vdev, buf, count,
+ ppos, false);
+ default:
+ if (pci_resource_flags(pdev, index) & IORESOURCE_IO)
+ return vfio_pci_io_readwrite(vdev, (char __user *)buf,
+ count, ppos, true);
+ if (pci_resource_flags(pdev, index) & IORESOURCE_MEM)
+ return vfio_pci_mem_readwrite(vdev, (char __user *)buf,
+ count, ppos, true);
}
return -EINVAL;
diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
index 611827c..203cf03 100644
--- a/drivers/vfio/pci/vfio_pci_private.h
+++ b/drivers/vfio/pci/vfio_pci_private.h
@@ -79,6 +79,12 @@ extern ssize_t vfio_pci_mem_readwrite(struct vfio_pci_device *vdev,
extern ssize_t vfio_pci_io_readwrite(struct vfio_pci_device *vdev,
char __user *buf, size_t count,
loff_t *ppos, bool iswrite);
+extern ssize_t vfio_pci_legacy_mem_readwrite(struct vfio_pci_device *vdev,
+ char __user *buf, size_t count,
+ loff_t *ppos, bool iswrite);
+extern ssize_t vfio_pci_legacy_io_readwrite(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 4362d9e..e0c905e 100644
--- a/drivers/vfio/pci/vfio_pci_rdwr.c
+++ b/drivers/vfio/pci/vfio_pci_rdwr.c
@@ -17,72 +17,44 @@
#include <linux/pci.h>
#include <linux/uaccess.h>
#include <linux/io.h>
+#include <linux/vgaarb.h>
#include "vfio_pci_private.h"
-/* I/O Port BAR access */
-ssize_t vfio_pci_io_readwrite(struct vfio_pci_device *vdev, char __user *buf,
- size_t count, loff_t *ppos, bool iswrite)
+static size_t do_io_rw(void __iomem *io, char __user *buf, size_t off,
+ size_t count, bool iswrite)
{
- struct pci_dev *pdev = vdev->pdev;
- loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
- int bar = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
- void __iomem *io;
size_t done = 0;
- if (!pci_resource_start(pdev, bar))
- return -EINVAL;
-
- if (pos + count > pci_resource_len(pdev, bar))
- return -EINVAL;
-
- if (!vdev->barmap[bar]) {
- int ret;
-
- ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
- if (ret)
- return ret;
-
- vdev->barmap[bar] = pci_iomap(pdev, bar, 0);
-
- if (!vdev->barmap[bar]) {
- pci_release_selected_regions(pdev, 1 << bar);
- return -EINVAL;
- }
- }
-
- io = vdev->barmap[bar];
-
while (count) {
int filled;
- if (count >= 3 && !(pos % 4)) {
+ if (count >= 4 && !(off % 4)) {
__le32 val;
if (iswrite) {
if (copy_from_user(&val, buf, 4))
return -EFAULT;
- iowrite32(le32_to_cpu(val), io + pos);
+ iowrite32(le32_to_cpu(val), io + off);
} else {
- val = cpu_to_le32(ioread32(io + pos));
+ val = cpu_to_le32(ioread32(io + off));
if (copy_to_user(buf, &val, 4))
return -EFAULT;
}
filled = 4;
-
- } else if ((pos % 2) == 0 && count >= 2) {
+ } else if (count >= 2 && !(off % 2)) {
__le16 val;
if (iswrite) {
if (copy_from_user(&val, buf, 2))
return -EFAULT;
- iowrite16(le16_to_cpu(val), io + pos);
+ iowrite16(le16_to_cpu(val), io + off);
} else {
- val = cpu_to_le16(ioread16(io + pos));
+ val = cpu_to_le16(ioread16(io + off));
if (copy_to_user(buf, &val, 2))
return -EFAULT;
@@ -96,9 +68,9 @@ ssize_t vfio_pci_io_readwrite(struct vfio_pci_device *vdev, char __user *buf,
if (copy_from_user(&val, buf, 1))
return -EFAULT;
- iowrite8(val, io + pos);
+ iowrite8(val, io + off);
} else {
- val = ioread8(io + pos);
+ val = ioread8(io + off);
if (copy_to_user(buf, &val, 1))
return -EFAULT;
@@ -109,11 +81,47 @@ ssize_t vfio_pci_io_readwrite(struct vfio_pci_device *vdev, char __user *buf,
count -= filled;
done += filled;
+ off += filled;
buf += filled;
- pos += filled;
}
- *ppos += done;
+ return done;
+}
+
+/* I/O Port BAR access */
+ssize_t vfio_pci_io_readwrite(struct vfio_pci_device *vdev, char __user *buf,
+ size_t count, loff_t *ppos, bool iswrite)
+{
+ struct pci_dev *pdev = vdev->pdev;
+ loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
+ int bar = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
+ size_t done;
+
+ if (!pci_resource_start(pdev, bar))
+ return -EINVAL;
+
+ if (pos + count > pci_resource_len(pdev, bar))
+ return -EINVAL;
+
+ if (!vdev->barmap[bar]) {
+ int ret;
+
+ ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
+ if (ret)
+ return ret;
+
+ vdev->barmap[bar] = pci_iomap(pdev, bar, 0);
+
+ if (!vdev->barmap[bar]) {
+ pci_release_selected_regions(pdev, 1 << bar);
+ return -EINVAL;
+ }
+ }
+
+ done = do_io_rw(vdev->barmap[bar], buf, pos, count, iswrite);
+
+ if (done >= 0)
+ *ppos += done;
return done;
}
@@ -267,3 +275,83 @@ out:
return count ? -EFAULT : done;
}
+
+ssize_t vfio_pci_legacy_mem_readwrite(struct vfio_pci_device *vdev,
+ char __user *buf, size_t count,
+ loff_t *ppos, bool iswrite)
+{
+ int ret;
+ loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
+
+ if ((vdev->pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA &&
+ pos >= 0xa0000 && pos < 0xc0000) {
+ void __iomem *mem;
+ size_t done;
+
+ if (pos + count > 0xc0000)
+ count = 0xc0000 - pos;
+
+ mem = ioremap_nocache(pos, count);
+ if (!mem)
+ return -ENOMEM;
+
+ ret = vga_get_interruptible(vdev->pdev, VGA_RSRC_LEGACY_MEM);
+ if (ret) {
+ iounmap(mem);
+ return ret;
+ }
+
+ done = do_io_rw(mem, buf, 0, count, iswrite);
+
+ vga_put(vdev->pdev, VGA_RSRC_LEGACY_MEM);
+ iounmap(mem);
+
+ if (done >= 0)
+ *ppos += done;
+
+ return done;
+ }
+
+ return -EINVAL;
+}
+
+ssize_t vfio_pci_legacy_io_readwrite(struct vfio_pci_device *vdev,
+ char __user *buf, size_t count,
+ loff_t *ppos, bool iswrite)
+{
+ int ret;
+ loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
+
+ if ((vdev->pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA &&
+ ((pos >= 0x3b0 && pos < 0x3bc) || (pos >= 0x3c0 && pos < 0x3e0))) {
+ void __iomem *io;
+ size_t done;
+
+ if (pos < 0x3bc && pos + count > 0x3bc)
+ count = 0x3bc - pos;
+ if (pos < 0x3e0 && pos + count > 0x3e0)
+ count = 0x3e0 - pos;
+
+ io = ioport_map(pos, count);
+ if (!io)
+ return -ENOMEM;
+
+ ret = vga_get_interruptible(vdev->pdev, VGA_RSRC_LEGACY_IO);
+ if (ret) {
+ ioport_unmap(io);
+ return ret;
+ }
+
+ done = do_io_rw(io, buf, 0, count, iswrite);
+
+ vga_put(vdev->pdev, VGA_RSRC_LEGACY_IO);
+ ioport_unmap(io);
+
+ if (done >= 0)
+ *ppos += done;
+
+ return done;
+ }
+
+ return -EINVAL;
+}
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 4758d1b..aa15851 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -147,6 +147,7 @@ struct vfio_device_info {
__u32 flags;
#define VFIO_DEVICE_FLAGS_RESET (1 << 0) /* Device supports reset */
#define VFIO_DEVICE_FLAGS_PCI (1 << 1) /* vfio-pci device */
+#define VFIO_DEVICE_FLAGS_VGA (1 << 2) /* Device supports VGA ranges */
__u32 num_regions; /* Max region index + 1 */
__u32 num_irqs; /* Max IRQ index + 1 */
};
@@ -303,6 +304,8 @@ enum {
VFIO_PCI_BAR5_REGION_INDEX,
VFIO_PCI_ROM_REGION_INDEX,
VFIO_PCI_CONFIG_REGION_INDEX,
+ VFIO_PCI_LEGACY_MMIO_REGION_INDEX,
+ VFIO_PCI_LEGACY_IOPORT_REGION_INDEX,
VFIO_PCI_NUM_REGIONS
};
^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2013-01-07 22:07 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-01-07 22:07 [PATCH 0/1] vfio-pci: Towards VGA support Alex Williamson
2013-01-07 22:07 ` [PATCH] vfio-pci: [NOT FOR COMMIT] Add support for legacy MMIO & I/O port towards " Alex Williamson
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox