Userspace patch for device assignment

Userspace patch for device assignment

[Amit Shah]

This patch is the userspace component to enable device assignment on kvm hosts. It uses the Intel IOMMU (VT-d) by default if available.

Assigning devices that share IRQ on the host is not supported yet. Attempt to assign a device that shares its irq with some other device results in a segfault in the pci_unregister_device code; I'm yet to fix that.

[PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Amit Shah]

From: Or Sagi <ors@tutis.com>
From: Nir Peleg <nir@tutis.com>
From: Amit Shah <amit.shah@qumranet.com>
From: Ben-Ami Yassour <benami@il.ibm.com>
From: Glauber de Oliveira Costa <gcosta@redhat.com>

With this patch, we can assign a device on the host machine to a
guest.

A new command-line option, -pcidevice is added.
For example, to invoke it for a device sitting at PCI bus:dev.fn
04:08.0 with host IRQ 18, use this:

	-pcidevice host=04:08.0

The host driver for the device, if any, is to be removed before
assigning the device.

This works only with the in-kernel irqchip method; to use the
userspace irqchip, a kernel module (irqhook) and some extra changes
are needed.

Signed-off-by: Amit Shah <amit.shah@qumranet.com>
---
 libkvm/libkvm-x86.c         |   14 +
 libkvm/libkvm.h             |   27 ++
 qemu/Makefile.target        |    1 +
 qemu/hw/device-assignment.c |  600 +++++++++++++++++++++++++++++++++++++++++++
 qemu/hw/device-assignment.h |   94 +++++++
 qemu/hw/isa.h               |    2 +
 qemu/hw/pc.c                |    9 +
 qemu/hw/pci.c               |   12 +
 qemu/hw/pci.h               |    1 +
 qemu/hw/piix_pci.c          |   19 ++
 qemu/vl.c                   |   18 ++
 11 files changed, 797 insertions(+), 0 deletions(-)
 create mode 100644 qemu/hw/device-assignment.c
 create mode 100644 qemu/hw/device-assignment.h

diff --git a/libkvm/libkvm-x86.c b/libkvm/libkvm-x86.c
index ea97bdd..831823b 100644
--- a/libkvm/libkvm-x86.c
+++ b/libkvm/libkvm-x86.c
@@ -126,6 +126,20 @@ static int kvm_init_tss(kvm_context_t kvm)
 	return 0;
 }
 
+#ifdef KVM_CAP_DEVICE_ASSIGNMENT
+int kvm_assign_pci_device(kvm_context_t kvm,
+			  struct kvm_assigned_pci_dev *assigned_dev)
+{
+	return ioctl(kvm->vm_fd, KVM_ASSIGN_PCI_DEVICE, assigned_dev);
+}
+
+int kvm_assign_irq(kvm_context_t kvm,
+		   struct kvm_assigned_irq *assigned_irq)
+{
+	return ioctl(kvm->vm_fd, KVM_ASSIGN_IRQ, assigned_irq);
+}
+#endif
+
 int kvm_arch_create_default_phys_mem(kvm_context_t kvm,
 				       unsigned long phys_mem_bytes,
 				       void **vm_mem)
diff --git a/libkvm/libkvm.h b/libkvm/libkvm.h
index 346eedf..b424af6 100644
--- a/libkvm/libkvm.h
+++ b/libkvm/libkvm.h
@@ -658,4 +658,31 @@ int kvm_s390_interrupt(kvm_context_t kvm, int slot,
 int kvm_s390_set_initial_psw(kvm_context_t kvm, int slot, psw_t psw);
 int kvm_s390_store_status(kvm_context_t kvm, int slot, unsigned long addr);
 #endif
+
+#ifdef KVM_CAP_DEVICE_ASSIGNMENT
+/*!
+ * \brief Notifies host kernel aboud a PCI device assigned to guest
+ *
+ * Used for PCI device assignment, this function notifies the host
+ * kernel about the assigning of the physical PCI device.
+ *
+ * \param kvm Pointer to the current kvm_context
+ * \param assigned_dev Parameters, like bus, devfn number, etc
+ */
+int kvm_assign_pci_device(kvm_context_t kvm,
+			  struct kvm_assigned_pci_dev *assigned_dev);
+
+/*!
+ * \brief Notifies host kernel about changes to a irq assignment
+ *
+ * Used for PCI device assignment, this function notifies the host
+ * kernel about the assigning of the irq for an assigned physical
+ * PCI device.
+ *
+ * \param kvm Pointer to the current kvm_context
+ * \param assigned_irq Parameters, like dev id, host irq, guest irq, etc
+ */
+int kvm_assign_irq(kvm_context_t kvm,
+		   struct kvm_assigned_irq *assigned_irq);
+#endif
 #endif
diff --git a/qemu/Makefile.target b/qemu/Makefile.target
index 2332fe3..750ecd5 100644
--- a/qemu/Makefile.target
+++ b/qemu/Makefile.target
@@ -611,6 +611,7 @@ OBJS+= ide.o pckbd.o ps2.o vga.o $(SOUND_HW) dma.o
 OBJS+= fdc.o mc146818rtc.o serial.o i8259.o i8254.o pcspk.o pc.o
 OBJS+= cirrus_vga.o apic.o parallel.o acpi.o piix_pci.o
 OBJS+= usb-uhci.o vmmouse.o vmport.o vmware_vga.o extboot.o
+OBJS+= device-assignment.o
 ifeq ($(USE_KVM_PIT), 1)
 OBJS+= i8254-kvm.o
 endif
diff --git a/qemu/hw/device-assignment.c b/qemu/hw/device-assignment.c
new file mode 100644
index 0000000..8bc4e5c
--- /dev/null
+++ b/qemu/hw/device-assignment.c
@@ -0,0 +1,600 @@
+/*
+ * Copyright (c) 2007, Neocleus Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ *
+ *  Assign a PCI device from the host to a guest VM.
+ *
+ *  Adapted for KVM by Qumranet.
+ *
+ *  Copyright (c) 2007, Neocleus, Alex Novik (alex@neocleus.com)
+ *  Copyright (c) 2007, Neocleus, Guy Zana (guy@neocleus.com)
+ *  Copyright (C) 2008, Qumranet, Amit Shah (amit.shah@qumranet.com)
+ */
+#include <stdio.h>
+#include <pthread.h>
+#include <sys/io.h>
+#include <sys/ioctl.h>
+#include <linux/types.h>
+
+/* From linux/ioport.h */
+#define IORESOURCE_IO		0x00000100	/* Resource type */
+#define IORESOURCE_MEM		0x00000200
+#define IORESOURCE_IRQ		0x00000400
+#define IORESOURCE_DMA		0x00000800
+#define IORESOURCE_PREFETCH	0x00001000	/* No side effects */
+
+#include "device-assignment.h"
+#include "irq.h"
+
+#include "qemu-kvm.h"
+#include <linux/kvm_para.h>
+
+extern FILE *logfile;
+
+/* #define DEVICE_ASSIGNMENT_DEBUG */
+
+#ifdef DEVICE_ASSIGNMENT_DEBUG
+#define DEBUG(fmt, args...) fprintf(stderr, "%s: " fmt, __func__ , ## args)
+#else
+#define DEBUG(fmt, args...)
+#endif
+
+#define assigned_dev_ioport_write(suffix)				\
+ static void assigned_dev_ioport_write##suffix(void *opaque, uint32_t addr, \
+					       uint32_t value)		\
+ {									\
+	 assigned_dev_region_t *r_access = (assigned_dev_region_t *)opaque; \
+	 uint32_t r_pio = (unsigned long)r_access->r_virtbase		\
+		 + (addr - r_access->e_physbase);			\
+	 if (r_access->debug & DEVICE_ASSIGNMENT_DEBUG_PIO) {		\
+		 fprintf(logfile, "assigned_dev_ioport_write" #suffix	\
+			 ": r_pio=%08x e_physbase=%08x"			\
+			 " r_virtbase=%08lx value=%08x\n", 		\
+			 r_pio, (int)r_access->e_physbase,		\
+			 (unsigned long)r_access->r_virtbase, value);	\
+	 }								\
+	 iopl(3);							\
+	 out##suffix(value, r_pio);					\
+  }
+
+assigned_dev_ioport_write(b)
+assigned_dev_ioport_write(w)
+assigned_dev_ioport_write(l)
+
+#define assigned_dev_ioport_read(suffix)				\
+ static uint32_t assigned_dev_ioport_read##suffix(void *opaque, uint32_t addr) \
+ {									\
+	 assigned_dev_region_t *r_access = (assigned_dev_region_t *)opaque; \
+	 uint32_t r_pio = (addr - r_access->e_physbase)			\
+		 + (unsigned long)r_access->r_virtbase;			\
+	 uint32_t value = in##suffix(r_pio);				\
+	 if (r_access->debug & DEVICE_ASSIGNMENT_DEBUG_PIO) {		\
+		 fprintf(logfile, "assigned_dev_ioport_read" #suffix	\
+			 ": r_pio=%08x e_physbase=%08x r_virtbase=%08lx " \
+			 "value=%08x\n", 				\
+			 r_pio, (int)r_access->e_physbase, 		\
+			 (unsigned long)r_access->r_virtbase, value);	\
+	 }								\
+	 return value;							\
+ }
+
+assigned_dev_ioport_read(b)
+assigned_dev_ioport_read(w)
+assigned_dev_ioport_read(l)
+
+static void assigned_dev_iomem_map(PCIDevice *pci_dev, int region_num,
+			 uint32_t e_phys, uint32_t e_size, int type)
+{
+	assigned_dev_t *r_dev = (assigned_dev_t *) pci_dev;
+	assigned_dev_region_t *region = &r_dev->v_addrs[region_num];
+	int first_map = (region->e_size == 0);
+	int ret = 0;
+
+	DEBUG("e_phys=%08x r_virt=%p type=%d len=%08x region_num=%d \n",
+	      e_phys, r_dev->v_addrs[region_num].r_virtbase, type, e_size,
+	      region_num);
+
+	region->e_physbase = e_phys;
+	region->e_size = e_size;
+
+	if (!first_map)
+		kvm_destroy_phys_mem(kvm_context, e_phys, e_size);
+	if (e_size > 0)
+		ret = kvm_register_userspace_phys_mem(kvm_context,
+						      e_phys,
+						      region->r_virtbase,
+						      e_size,
+						      0);
+	if (ret != 0)
+		fprintf(logfile, "%s: Error: create new mapping failed\n",
+			__func__);
+}
+
+static void assigned_dev_ioport_map(PCIDevice *pci_dev, int region_num,
+				    uint32_t addr, uint32_t size, int type)
+{
+	assigned_dev_t *r_dev = (assigned_dev_t *) pci_dev;
+	int i;
+	uint32_t ((*rf[])(void *, uint32_t)) =
+		{ assigned_dev_ioport_readb,
+		  assigned_dev_ioport_readw,
+		  assigned_dev_ioport_readl
+		};
+	void ((*wf[])(void *, uint32_t, uint32_t)) =
+		{ assigned_dev_ioport_writeb,
+		  assigned_dev_ioport_writew,
+		  assigned_dev_ioport_writel
+		};
+
+	r_dev->v_addrs[region_num].e_physbase = addr;
+	DEBUG("%s: address=0x%x type=0x%x len=%d region_num=%d \n",
+	      __func__, addr, type, size, region_num);
+
+	for (i = 0; i < 3; i++) {
+		register_ioport_write(addr, size, 1<<i, wf[i],
+				      (void *) (r_dev->v_addrs + region_num));
+		register_ioport_read(addr, size, 1<<i, rf[i],
+				     (void *) (r_dev->v_addrs + region_num));
+	}
+}
+
+static void assigned_dev_pci_write_config(PCIDevice *d, uint32_t address,
+					  uint32_t val, int len)
+{
+	int fd, r;
+
+	DEBUG("%s: (%x.%x): address=%04x val=0x%08x len=%d\n",
+	      __func__, ((d->devfn >> 3) & 0x1F), (d->devfn & 0x7),
+	      (uint16_t) address, val, len);
+
+	if (address == 0x4)
+		pci_default_write_config(d, address, val, len);
+
+	if ((address >= 0x10 && address <= 0x24) || address == 0x34 ||
+	    address == 0x3c || address == 0x3d) {
+		/* used for update-mappings (BAR emulation) */
+		pci_default_write_config(d, address, val, len);
+		return;
+	}
+	DEBUG("%s: NON BAR (%x.%x): address=%04x val=0x%08x len=%d\n",
+	      __func__, ((d->devfn >> 3) & 0x1F), (d->devfn & 0x7),
+	      (uint16_t) address, val, len);
+	fd = ((assigned_dev_t *)d)->real_device.config_fd;
+	lseek(fd, address, SEEK_SET);
+again:
+	r = write(fd, &val, len);
+	if (r < 0) {
+		if (errno == EINTR || errno == EAGAIN)
+			goto again;
+		fprintf(stderr, "%s: write failed, errno = %d\n",
+			__func__, errno);
+	}
+}
+
+static uint32_t assigned_dev_pci_read_config(PCIDevice *d, uint32_t address,
+					     int len)
+{
+	uint32_t val = 0;
+	int fd, r;
+
+	if ((address >= 0x10 && address <= 0x24) || address == 0x34 ||
+	    address == 0x3c || address == 0x3d) {
+		val = pci_default_read_config(d, address, len);
+		DEBUG("(%x.%x): address=%04x val=0x%08x len=%d\n",
+		      (d->devfn >> 3) & 0x1F, (d->devfn & 0x7), address, val,
+		      len);
+		return val;
+	}
+
+	/* vga specific, remove later */
+	if (address == 0xFC)
+		goto do_log;
+
+	fd = ((assigned_dev_t *)d)->real_device.config_fd;
+	lseek(fd, address, SEEK_SET);
+again:
+	r = read(fd, &val, len);
+	if (r < 0) {
+		if (errno == EINTR || errno == EAGAIN)
+			goto again;
+		fprintf(stderr, "%s: read failed, errno = %d\n",
+			__func__, errno);
+	}
+do_log:
+	DEBUG("(%x.%x): address=%04x val=0x%08x len=%d\n",
+	      (d->devfn >> 3) & 0x1F, (d->devfn & 0x7), address, val, len);
+
+	/* kill the special capabilities */
+	if (address == 4 && len == 4)
+		val &= ~0x100000;
+	else if (address == 6)
+		val &= ~0x10;
+
+	return val;
+}
+
+static int assigned_dev_register_regions(pci_region_t *io_regions,
+					 unsigned long regions_num,
+					 assigned_dev_t *pci_dev)
+{
+	uint32_t i;
+	pci_region_t *cur_region = io_regions;
+
+	for (i = 0; i < regions_num; i++, cur_region++) {
+		if (!cur_region->valid)
+			continue;
+#ifdef DEVICE_ASSIGNMENT_DEBUG
+		pci_dev->v_addrs[i].debug |= DEVICE_ASSIGNMENT_DEBUG_MMIO
+					     | DEVICE_ASSIGNMENT_DEBUG_PIO;
+#endif
+		pci_dev->v_addrs[i].num = i;
+
+		/* handle memory io regions */
+		if (cur_region->type & IORESOURCE_MEM) {
+			int t = cur_region->type & IORESOURCE_PREFETCH
+				? PCI_ADDRESS_SPACE_MEM_PREFETCH
+				: PCI_ADDRESS_SPACE_MEM;
+
+			/* map physical memory */
+			pci_dev->v_addrs[i].e_physbase = cur_region->base_addr;
+			pci_dev->v_addrs[i].r_virtbase =
+				mmap(NULL,
+				     (cur_region->size + 0xFFF) & 0xFFFFF000,
+				     PROT_WRITE | PROT_READ, MAP_SHARED,
+				     cur_region->resource_fd, (off_t) 0);
+
+			if ((void *) -1 == pci_dev->v_addrs[i].r_virtbase) {
+				fprintf(stderr, "%s: Error: Couldn't mmap 0x%x!"
+					"\n", __func__,
+					(uint32_t) (cur_region->base_addr));
+				return -1;
+			}
+			pci_dev->v_addrs[i].r_size = cur_region->size;
+			pci_dev->v_addrs[i].e_size = 0;
+
+			/* add offset */
+			pci_dev->v_addrs[i].r_virtbase +=
+				(cur_region->base_addr & 0xFFF);
+
+			pci_register_io_region((PCIDevice *) pci_dev, i,
+					       cur_region->size, t,
+					       assigned_dev_iomem_map);
+			continue;
+		}
+		/* handle port io regions */
+		pci_register_io_region((PCIDevice *) pci_dev, i,
+				       cur_region->size, PCI_ADDRESS_SPACE_IO,
+				       assigned_dev_ioport_map);
+
+		pci_dev->v_addrs[i].e_physbase = cur_region->base_addr;
+		pci_dev->v_addrs[i].r_virtbase =
+			(void *)(long)cur_region->base_addr;
+		/* not relevant for port io */
+		pci_dev->v_addrs[i].memory_index = 0;
+	}
+
+	/* success */
+	return 0;
+}
+
+static int get_real_device(assigned_dev_t *pci_dev, uint8_t r_bus,
+			   uint8_t r_dev, uint8_t r_func)
+{
+	char dir[128], name[128], comp[16];
+	int fd, r = 0;
+	FILE *f;
+	unsigned long long start, end, size, flags;
+	pci_region_t *rp;
+	pci_dev_t *dev = &pci_dev->real_device;
+
+	dev->region_number = 0;
+
+	sprintf(dir, "/sys/bus/pci/devices/0000:%02x:%02x.%x/",
+		r_bus, r_dev, r_func);
+	strcpy(name, dir);
+	strcat(name, "config");
+	fd = open(name, O_RDWR);
+	if (fd == -1) {
+		fprintf(stderr, "%s: %s: %m\n", __func__, name);
+		return 1;
+	}
+	dev->config_fd = fd;
+again:
+	r = read(fd, pci_dev->dev.config, sizeof pci_dev->dev.config);
+	if (r < 0) {
+		if (errno == EINTR || errno == EAGAIN)
+			goto again;
+		fprintf(stderr, "%s: read failed, errno = %d\n",
+			__func__, errno);
+	}
+	strcpy(name, dir);
+	strcat(name, "resource");
+
+	f = fopen(name, "r");
+	if (f == NULL) {
+		fprintf(stderr, "%s: %s: %m\n", __func__, name);
+		return 1;
+	}
+	for (r = 0; fscanf(f, "%lli %lli %lli\n", &start, &end, &flags) == 3;
+	     r++) {
+		rp = dev->regions + r;
+		rp->valid = 0;
+		size = end - start + 1;
+		flags &= IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH;
+		if (size == 0 || (flags & ~IORESOURCE_PREFETCH) == 0)
+			continue;
+		if (flags & IORESOURCE_MEM) {
+			flags &= ~IORESOURCE_IO;
+			sprintf(comp, "resource%d", r);
+			strcpy(name, dir);
+			strcat(name, comp);
+			fd = open(name, O_RDWR);
+			if (fd == -1)
+				continue;		/* probably ROM */
+			rp->resource_fd = fd;
+		} else
+			flags &= ~IORESOURCE_PREFETCH;
+
+		rp->type = flags;
+		rp->valid = 1;
+		rp->base_addr = start;
+		rp->size = size;
+		DEBUG("%s: region %d size %d start 0x%x type %d "
+		      "resource_fd %d\n", __func__, r, rp->size, start,
+		      rp->type, rp->resource_fd);
+	}
+	fclose(f);
+
+	dev->region_number = r;
+	return 0;
+}
+
+static uint32_t calc_assigned_dev_id(uint8_t bus, uint8_t devfn)
+{
+	return (uint32_t)bus << 8 | (uint32_t)devfn;
+}
+
+static assigned_dev_t *register_real_device(PCIBus *e_bus,
+					    const char *e_dev_name,
+					    int e_devfn, uint8_t r_bus,
+					    uint8_t r_dev, uint8_t r_func,
+					    int flags)
+{
+	int rc;
+	assigned_dev_t *pci_dev;
+	uint8_t e_device, e_intx;
+
+	DEBUG("%s: Registering real physical device %s (devfn=0x%x)\n",
+	      __func__, e_dev_name, e_devfn);
+
+	pci_dev = (assigned_dev_t *)
+		pci_register_device(e_bus, e_dev_name, sizeof(assigned_dev_t),
+				    e_devfn, assigned_dev_pci_read_config,
+				    assigned_dev_pci_write_config);
+	if (NULL == pci_dev) {
+		fprintf(stderr, "%s: Error: Couldn't register real device %s\n",
+			__func__, e_dev_name);
+		return NULL;
+	}
+	if (get_real_device(pci_dev, r_bus, r_dev, r_func)) {
+		fprintf(stderr, "%s: Error: Couldn't get real device (%s)!\n",
+			__func__, e_dev_name);
+		goto out;
+	}
+
+	/* handle real device's MMIO/PIO BARs */
+	if (assigned_dev_register_regions(pci_dev->real_device.regions,
+					  pci_dev->real_device.region_number,
+					  pci_dev))
+		goto out;
+
+	/* handle interrupt routing */
+	e_device = (pci_dev->dev.devfn >> 3) & 0x1f;
+	e_intx = pci_dev->dev.config[0x3d] - 1;
+	pci_dev->intpin = e_intx;
+	pci_dev->run = 0;
+	pci_dev->girq = 0;
+	pci_dev->h_busnr = r_bus;
+	pci_dev->h_devfn = PCI_DEVFN(r_dev, r_func);
+
+#ifdef KVM_CAP_DEVICE_ASSIGNMENT
+	if (kvm_enabled()) {
+		struct kvm_assigned_pci_dev assigned_dev_data;
+
+		memset(&assigned_dev_data, 0, sizeof(assigned_dev_data));
+		assigned_dev_data.assigned_dev_id  =
+			calc_assigned_dev_id(pci_dev->h_busnr,
+					     (uint32_t)pci_dev->h_devfn);
+		assigned_dev_data.busnr = pci_dev->h_busnr;
+		assigned_dev_data.devfn = pci_dev->h_devfn;
+		assigned_dev_data.flags = flags;
+		rc = kvm_assign_pci_device(kvm_context,
+					   &assigned_dev_data);
+		if (rc < 0) {
+			fprintf(stderr, "Could not notify kernel about "
+				"assigned device \"%s\"\n", e_dev_name);
+			perror("pt-ioctl");
+			goto out;
+		}
+	}
+#endif
+	fprintf(logfile, "Registered host PCI device %02x:%02x.%1x "
+		"(\"%s\") as guest device %02x:%02x.%1x\n",
+		r_bus, r_dev, r_func, e_dev_name,
+		pci_bus_num(e_bus), e_device, r_func);
+
+	return pci_dev;
+out:
+	pci_unregister_device(&pci_dev->dev);
+	return NULL;
+}
+
+#define	MAX_ASSIGNED_DEVS 4
+struct {
+	char name[15];
+	int bus;
+	int dev;
+	int func;
+	int dma;
+	assigned_dev_t *assigned_dev;
+} assigned_devices[MAX_ASSIGNED_DEVS];
+
+int nr_assigned_devices;
+extern int get_param_value(char *buf, int buf_size,
+			   const char *tag, const char *str);
+extern int piix_get_irq(int);
+
+#ifdef KVM_CAP_DEVICE_ASSIGNMENT
+/* The pci config space got updated. Check if irq numbers have changed
+ * for our devices
+ */
+void assigned_dev_update_irq(PCIDevice *d)
+{
+	int i, irq, r;
+	assigned_dev_t *assigned_dev;
+
+	for (i = 0; i < nr_assigned_devices; i++) {
+		assigned_dev = assigned_devices[i].assigned_dev;
+		if (assigned_dev == NULL)
+			continue;
+
+		irq = pci_map_irq(&assigned_dev->dev, assigned_dev->intpin);
+		irq = piix_get_irq(irq);
+
+		if (irq != assigned_dev->girq) {
+			struct kvm_assigned_irq assigned_irq_data;
+
+			memset(&assigned_irq_data, 0, sizeof assigned_irq_data);
+			assigned_irq_data.assigned_dev_id  =
+				calc_assigned_dev_id(assigned_dev->h_busnr,
+						     (uint8_t)
+						     assigned_dev->h_devfn);
+			assigned_irq_data.guest_irq = irq;
+			assigned_irq_data.host_irq =
+				assigned_dev->real_device.irq;
+			r = kvm_assign_irq(kvm_context, &assigned_irq_data);
+			if (r < 0) {
+				perror("assigned_dev_update_irq");
+				pci_unregister_device(&assigned_dev->dev);
+				continue;
+			}
+			assigned_dev->girq = irq;
+		}
+	}
+}
+#endif
+
+static int init_device_assignment(void)
+{
+	/* Do we have any devices to be assigned? */
+	if (nr_assigned_devices == 0)
+		return -1;
+	iopl(3);
+	return 0;
+}
+
+int init_assigned_device(PCIBus *bus, int *index)
+{
+	assigned_dev_t *dev = NULL;
+	int i, ret = 0;
+
+	if (*index == -1) {
+		if (init_device_assignment() < 0)
+			return -1;
+
+		*index = nr_assigned_devices - 1;
+	}
+	i = *index;
+	dev = register_real_device(bus, assigned_devices[i].name, -1,
+				   assigned_devices[i].bus,
+				   assigned_devices[i].dev,
+				   assigned_devices[i].func,
+				   assigned_devices[i].dma);
+	if (dev == NULL) {
+		fprintf(stderr, "Error: Couldn't register device \"%s\"\n",
+			assigned_devices[i].name);
+		ret = -1;
+	}
+	assigned_devices[i].assigned_dev = dev;
+
+	--*index;
+	return ret;
+}
+
+/*
+ * Syntax to assign device:
+ *
+ * -pcidevice dev=bus:dev.func,dma=dma
+ *
+ * Example:
+ * -pcidevice dev=00:13.0,dma=pvdma
+ *
+ * dma can currently be 'none' to disable iommu support.
+ */
+void add_assigned_device(const char *arg)
+{
+	char *cp, *cp1;
+	char device[8];
+	char dma[6];
+	int r;
+
+	if (nr_assigned_devices >= MAX_ASSIGNED_DEVS) {
+		fprintf(stderr, "Too many assigned devices (max %d)\n",
+			MAX_ASSIGNED_DEVS);
+		return;
+	}
+	memset(&assigned_devices[nr_assigned_devices], 0,
+	       sizeof assigned_devices[nr_assigned_devices]);
+
+	r = get_param_value(device, sizeof device, "host", arg);
+
+	r = get_param_value(assigned_devices[nr_assigned_devices].name,
+			    sizeof assigned_devices[nr_assigned_devices].name,
+			    "name", arg);
+	if (!r)
+		strncpy(assigned_devices[nr_assigned_devices].name, device, 8);
+
+#ifdef KVM_CAP_IOMMU
+	r = kvm_check_extension(kvm_context, KVM_CAP_IOMMU);
+	if (r)
+		assigned_devices[nr_assigned_devices].dma |=
+			KVM_DEV_ASSIGN_ENABLE_IOMMU;
+
+	r = get_param_value(dma, sizeof dma, "dma", arg);
+	if (r && !strncmp(dma, "none", 4)) {
+		assigned_devices[nr_assigned_devices].dma &=
+			~KVM_DEV_ASSIGN_ENABLE_IOMMU;
+	}
+#endif
+	cp = device;
+	assigned_devices[nr_assigned_devices].bus = strtoul(cp, &cp1, 16);
+	if (*cp1 != ':')
+		goto bad;
+	cp = cp1 + 1;
+
+	assigned_devices[nr_assigned_devices].dev = strtoul(cp, &cp1, 16);
+	if (*cp1 != '.')
+		goto bad;
+	cp = cp1 + 1;
+
+	assigned_devices[nr_assigned_devices].func = strtoul(cp, &cp1, 16);
+
+	nr_assigned_devices++;
+	return;
+bad:
+	fprintf(stderr, "pcidevice argument parse error; "
+		"please check the help text for usage\n");
+}
diff --git a/qemu/hw/device-assignment.h b/qemu/hw/device-assignment.h
new file mode 100644
index 0000000..1f2945e
--- /dev/null
+++ b/qemu/hw/device-assignment.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2007, Neocleus Corporation.
+ * Copyright (c) 2007, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ *  Data structures for storing PCI state
+ *
+ *  Adapted to kvm by Qumranet
+ *
+ *  Copyright (c) 2007, Neocleus, Alex Novik (alex@neocleus.com)
+ *  Copyright (c) 2007, Neocleus, Guy Zana (guy@neocleus.com)
+ *  Copyright (C) 2008, Qumranet, Amit Shah (amit.shah@qumranet.com)
+ */
+
+#ifndef __DEVICE_ASSIGNMENT_H__
+#define __DEVICE_ASSIGNMENT_H__
+
+#include <sys/mman.h>
+#include "qemu-common.h"
+#include "pci.h"
+#include <linux/types.h>
+
+#define DEVICE_ASSIGNMENT_DEBUG_PIO	(0x01)
+#define DEVICE_ASSIGNMENT_DEBUG_MMIO	(0x02)
+
+/* From include/linux/pci.h in the kernel sources */
+#define PCI_DEVFN(slot,func)	((((slot) & 0x1f) << 3) | ((func) & 0x07))
+
+typedef uint32_t pciaddr_t;
+
+#define MAX_IO_REGIONS			(6)
+
+typedef struct pci_region_s {
+	int type;	/* Memory or port I/O */
+	int valid;
+	pciaddr_t base_addr;
+	pciaddr_t size;		/* size of the region */
+	int resource_fd;
+} pci_region_t;
+
+typedef struct pci_dev_s {
+	uint8_t bus, dev, func;	/* Bus inside domain, device and function */
+	int irq;		/* IRQ number */
+	uint16_t region_number;	/* number of active regions */
+
+	/* Port I/O or MMIO Regions */
+	pci_region_t regions[MAX_IO_REGIONS];
+	int config_fd;
+} pci_dev_t;
+
+typedef struct assigned_dev_region_s {
+	target_phys_addr_t e_physbase;
+	uint32_t memory_index;
+	void *r_virtbase;	/* mmapped access address */
+	int num;		/* our index within v_addrs[] */
+	uint32_t e_size;        /* emulated size of region in bytes */
+	uint32_t r_size;        /* real size of region in bytes */
+	uint32_t debug;
+} assigned_dev_region_t;
+
+typedef struct assigned_dev_s {
+	PCIDevice dev;
+	int intpin;
+	uint8_t debug_flags;
+	assigned_dev_region_t v_addrs[PCI_NUM_REGIONS];
+	pci_dev_t real_device;
+	int run;
+	int girq;
+	unsigned char h_busnr;
+	unsigned int h_devfn;
+	int bound;
+} assigned_dev_t;
+
+/* Initialization functions */
+int init_assigned_device(PCIBus *bus, int *index);
+void add_assigned_device(const char *arg);
+void assigned_dev_set_vector(int irq, int vector);
+void assigned_dev_ack_mirq(int vector);
+
+#define logfile stderr
+
+#endif				/* __DEVICE_ASSIGNMENT_H__ */
diff --git a/qemu/hw/isa.h b/qemu/hw/isa.h
index 89b3004..c720f5e 100644
--- a/qemu/hw/isa.h
+++ b/qemu/hw/isa.h
@@ -1,5 +1,7 @@
 /* ISA bus */
 
+#include "hw.h"
+
 extern target_phys_addr_t isa_mem_base;
 
 int register_ioport_read(int start, int length, int size,
diff --git a/qemu/hw/pc.c b/qemu/hw/pc.c
index 10d7269..4e3eafe 100644
--- a/qemu/hw/pc.c
+++ b/qemu/hw/pc.c
@@ -32,6 +32,7 @@
 #include "smbus.h"
 #include "boards.h"
 #include "console.h"
+#include "device-assignment.h"
 
 #include "qemu-kvm.h"
 
@@ -1003,6 +1004,14 @@ static void pc_init1(ram_addr_t ram_size, int vga_ram_size,
         }
     }
 
+    /* Initialize assigned devices */
+    if (pci_enabled) {
+        int r = -1;
+        do {
+            init_assigned_device(pci_bus, &r);
+	} while (r >= 0);
+    }
+
     rtc_state = rtc_init(0x70, i8259[8]);
 
     qemu_register_boot_set(pc_boot_set, rtc_state);
diff --git a/qemu/hw/pci.c b/qemu/hw/pci.c
index 92683d1..ef85a4a 100644
--- a/qemu/hw/pci.c
+++ b/qemu/hw/pci.c
@@ -50,6 +50,7 @@ struct PCIBus {
 
 static void pci_update_mappings(PCIDevice *d);
 static void pci_set_irq(void *opaque, int irq_num, int level);
+void assigned_dev_update_irq(PCIDevice *d);
 
 target_phys_addr_t pci_mem_base;
 static int pci_irq_index;
@@ -453,6 +454,12 @@ void pci_default_write_config(PCIDevice *d,
         val >>= 8;
     }
 
+#ifdef KVM_CAP_DEVICE_ASSIGNMENT
+    if (kvm_enabled() && qemu_kvm_irqchip_in_kernel() &&
+	address >= 0x60 && address <= 0x63)
+	assigned_dev_update_irq(d);
+#endif
+
     end = address + len;
     if (end > PCI_COMMAND && address < (PCI_COMMAND + 2)) {
         /* if the command register is modified, we must modify the mappings */
@@ -555,6 +562,11 @@ static void pci_set_irq(void *opaque, int irq_num, int level)
     bus->set_irq(bus->irq_opaque, irq_num, bus->irq_count[irq_num] != 0);
 }
 
+int pci_map_irq(PCIDevice *pci_dev, int pin)
+{
+	return pci_dev->bus->map_irq(pci_dev, pin);
+}
+
 /***********************************************************/
 /* monitor info on PCI */
 
diff --git a/qemu/hw/pci.h b/qemu/hw/pci.h
index 60e4094..e11fbbf 100644
--- a/qemu/hw/pci.h
+++ b/qemu/hw/pci.h
@@ -81,6 +81,7 @@ void pci_register_io_region(PCIDevice *pci_dev, int region_num,
                             uint32_t size, int type,
                             PCIMapIORegionFunc *map_func);
 
+int pci_map_irq(PCIDevice *pci_dev, int pin);
 uint32_t pci_default_read_config(PCIDevice *d,
                                  uint32_t address, int len);
 void pci_default_write_config(PCIDevice *d,
diff --git a/qemu/hw/piix_pci.c b/qemu/hw/piix_pci.c
index 90cb3a6..112381a 100644
--- a/qemu/hw/piix_pci.c
+++ b/qemu/hw/piix_pci.c
@@ -237,6 +237,25 @@ static void piix3_set_irq(qemu_irq *pic, int irq_num, int level)
     }
 }
 
+int piix3_get_pin(int pic_irq)
+{
+    int i;
+    for (i = 0; i < 4; i++)
+        if (piix3_dev->config[0x60+i] == pic_irq)
+            return i;
+    return -1;
+}
+
+int piix_get_irq(int pin)
+{
+    if (piix3_dev)
+        return piix3_dev->config[0x60+pin];
+    if (piix4_dev)
+        return piix4_dev->config[0x60+pin];
+
+    return 0;
+}
+
 static void piix3_reset(PCIDevice *d)
 {
     uint8_t *pci_conf = d->config;
diff --git a/qemu/vl.c b/qemu/vl.c
index 17cfdfc..85718a5 100644
--- a/qemu/vl.c
+++ b/qemu/vl.c
@@ -37,6 +37,7 @@
 #include "qemu-char.h"
 #include "block.h"
 #include "audio/audio.h"
+#include "hw/device-assignment.h"
 #include "migration.h"
 #include "qemu-kvm.h"
 
@@ -8439,6 +8440,12 @@ static void help(int exitcode)
 #endif
 	   "-no-kvm-irqchip disable KVM kernel mode PIC/IOAPIC/LAPIC\n"
 	   "-no-kvm-pit	    disable KVM kernel mode PIT\n"
+#if defined(TARGET_I386) || defined(TARGET_X86_64)
+	   "-pcidevice host=bus:dev.func[,dma=none][,name=\"string\"]\n"
+	   "                expose a PCI device to the guest OS.\n"
+	   "                dma=none: don't perform any dma translations (default is to use an iommu)\n"
+	   "                'string' is used in log output.\n"
+#endif
 #endif
 #ifdef TARGET_I386
            "-std-vga        simulate a standard VGA card with VESA Bochs Extensions\n"
@@ -8562,6 +8569,9 @@ enum {
     QEMU_OPTION_no_kvm,
     QEMU_OPTION_no_kvm_irqchip,
     QEMU_OPTION_no_kvm_pit,
+#if defined(TARGET_I386) || defined(TARGET_X86_64)
+    QEMU_OPTION_pcidevice,
+#endif
     QEMU_OPTION_no_reboot,
     QEMU_OPTION_no_shutdown,
     QEMU_OPTION_show_cursor,
@@ -8650,6 +8660,9 @@ const QEMUOption qemu_options[] = {
 #endif
     { "no-kvm-irqchip", 0, QEMU_OPTION_no_kvm_irqchip },
     { "no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit },
+#if defined(TARGET_I386) || defined(TARGET_X86_64)
+    { "pcidevice", HAS_ARG, QEMU_OPTION_pcidevice },
+#endif
 #endif
 #if defined(TARGET_PPC) || defined(TARGET_SPARC)
     { "g", 1, QEMU_OPTION_g },
@@ -9554,6 +9567,11 @@ int main(int argc, char **argv)
 		kvm_pit = 0;
 		break;
 	    }
+#if defined(TARGET_I386) || defined(TARGET_X86_64)
+	    case QEMU_OPTION_pcidevice:
+		add_assigned_device(optarg);
+		break;
+#endif
 #endif
             case QEMU_OPTION_usb:
                 usb_enabled = 1;
-- 
1.5.4.3

Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Ben-Ami Yassour]

On Tue, 2008-08-26 at 18:29 +0300, Amit Shah wrote:
> From: Or Sagi <ors@tutis.com>
> From: Nir Peleg <nir@tutis.com>
> From: Amit Shah <amit.shah@qumranet.com>
> From: Ben-Ami Yassour <benami@il.ibm.com>
> From: Glauber de Oliveira Costa <gcosta@redhat.com>
> With this patch, we can assign a device on the host machine to a
> guest.
> 
> A new command-line option, -pcidevice is added.
> For example, to invoke it for a device sitting at PCI bus:dev.fn
> 04:08.0 with host IRQ 18, use this:
> 
> 	-pcidevice host=04:08.0
> 
> The host driver for the device, if any, is to be removed before
> assigning the device.
> 
> This works only with the in-kernel irqchip method; to use the
> userspace irqchip, a kernel module (irqhook) and some extra changes
> are needed.
> 
> Signed-off-by: Amit Shah <amit.shah@qumranet.com>
> ---
>  libkvm/libkvm-x86.c         |   14 +
>  libkvm/libkvm.h             |   27 ++
>  qemu/Makefile.target        |    1 +
>  qemu/hw/device-assignment.c |  600 +++++++++++++++++++++++++++++++++++++++++++
>  qemu/hw/device-assignment.h |   94 +++++++
>  qemu/hw/isa.h               |    2 +
>  qemu/hw/pc.c                |    9 +
>  qemu/hw/pci.c               |   12 +
>  qemu/hw/pci.h               |    1 +
>  qemu/hw/piix_pci.c          |   19 ++
>  qemu/vl.c                   |   18 ++
>  11 files changed, 797 insertions(+), 0 deletions(-)
>  create mode 100644 qemu/hw/device-assignment.c
>  create mode 100644 qemu/hw/device-assignment.h
> 
> diff --git a/libkvm/libkvm-x86.c b/libkvm/libkvm-x86.c
> index ea97bdd..831823b 100644
> --- a/libkvm/libkvm-x86.c
> +++ b/libkvm/libkvm-x86.c
> @@ -126,6 +126,20 @@ static int kvm_init_tss(kvm_context_t kvm)
>  	return 0;
>  }
>  
> +#ifdef KVM_CAP_DEVICE_ASSIGNMENT
> +int kvm_assign_pci_device(kvm_context_t kvm,
> +			  struct kvm_assigned_pci_dev *assigned_dev)
> +{
> +	return ioctl(kvm->vm_fd, KVM_ASSIGN_PCI_DEVICE, assigned_dev);
> +}
> +
> +int kvm_assign_irq(kvm_context_t kvm,
> +		   struct kvm_assigned_irq *assigned_irq)
> +{
> +	return ioctl(kvm->vm_fd, KVM_ASSIGN_IRQ, assigned_irq);
> +}
> +#endif
> +
>  int kvm_arch_create_default_phys_mem(kvm_context_t kvm,
>  				       unsigned long phys_mem_bytes,
>  				       void **vm_mem)
> diff --git a/libkvm/libkvm.h b/libkvm/libkvm.h
> index 346eedf..b424af6 100644
> --- a/libkvm/libkvm.h
> +++ b/libkvm/libkvm.h
> @@ -658,4 +658,31 @@ int kvm_s390_interrupt(kvm_context_t kvm, int slot,
>  int kvm_s390_set_initial_psw(kvm_context_t kvm, int slot, psw_t psw);
>  int kvm_s390_store_status(kvm_context_t kvm, int slot, unsigned long addr);
>  #endif
> +
> +#ifdef KVM_CAP_DEVICE_ASSIGNMENT
> +/*!
> + * \brief Notifies host kernel aboud a PCI device assigned to guest
> + *
> + * Used for PCI device assignment, this function notifies the host
> + * kernel about the assigning of the physical PCI device.
> + *
> + * \param kvm Pointer to the current kvm_context
> + * \param assigned_dev Parameters, like bus, devfn number, etc
> + */
> +int kvm_assign_pci_device(kvm_context_t kvm,
> +			  struct kvm_assigned_pci_dev *assigned_dev);
> +
> +/*!
> + * \brief Notifies host kernel about changes to a irq assignment
> + *
> + * Used for PCI device assignment, this function notifies the host
> + * kernel about the assigning of the irq for an assigned physical
> + * PCI device.
> + *
> + * \param kvm Pointer to the current kvm_context
> + * \param assigned_irq Parameters, like dev id, host irq, guest irq, etc
> + */
> +int kvm_assign_irq(kvm_context_t kvm,
> +		   struct kvm_assigned_irq *assigned_irq);
> +#endif
>  #endif
> diff --git a/qemu/Makefile.target b/qemu/Makefile.target
> index 2332fe3..750ecd5 100644
> --- a/qemu/Makefile.target
> +++ b/qemu/Makefile.target
> @@ -611,6 +611,7 @@ OBJS+= ide.o pckbd.o ps2.o vga.o $(SOUND_HW) dma.o
>  OBJS+= fdc.o mc146818rtc.o serial.o i8259.o i8254.o pcspk.o pc.o
>  OBJS+= cirrus_vga.o apic.o parallel.o acpi.o piix_pci.o
>  OBJS+= usb-uhci.o vmmouse.o vmport.o vmware_vga.o extboot.o
> +OBJS+= device-assignment.o
>  ifeq ($(USE_KVM_PIT), 1)
>  OBJS+= i8254-kvm.o
>  endif
> diff --git a/qemu/hw/device-assignment.c b/qemu/hw/device-assignment.c
> new file mode 100644
> index 0000000..8bc4e5c
> --- /dev/null
> +++ b/qemu/hw/device-assignment.c
> @@ -0,0 +1,600 @@
> +/*
> + * Copyright (c) 2007, Neocleus Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
> + * Place - Suite 330, Boston, MA 02111-1307 USA.
> + *
> + *
> + *  Assign a PCI device from the host to a guest VM.
> + *
> + *  Adapted for KVM by Qumranet.
> + *
> + *  Copyright (c) 2007, Neocleus, Alex Novik (alex@neocleus.com)
> + *  Copyright (c) 2007, Neocleus, Guy Zana (guy@neocleus.com)
> + *  Copyright (C) 2008, Qumranet, Amit Shah (amit.shah@qumranet.com)
> + */
> +#include <stdio.h>
> +#include <pthread.h>
> +#include <sys/io.h>
> +#include <sys/ioctl.h>
> +#include <linux/types.h>
> +
> +/* From linux/ioport.h */
> +#define IORESOURCE_IO		0x00000100	/* Resource type */
> +#define IORESOURCE_MEM		0x00000200
> +#define IORESOURCE_IRQ		0x00000400
> +#define IORESOURCE_DMA		0x00000800
> +#define IORESOURCE_PREFETCH	0x00001000	/* No side effects */
> +
> +#include "device-assignment.h"
> +#include "irq.h"
> +
> +#include "qemu-kvm.h"
> +#include <linux/kvm_para.h>
> +
> +extern FILE *logfile;
> +
> +/* #define DEVICE_ASSIGNMENT_DEBUG */
> +
> +#ifdef DEVICE_ASSIGNMENT_DEBUG
> +#define DEBUG(fmt, args...) fprintf(stderr, "%s: " fmt, __func__ , ## args)
> +#else
> +#define DEBUG(fmt, args...)
> +#endif
> +
> +#define assigned_dev_ioport_write(suffix)				\
> + static void assigned_dev_ioport_write##suffix(void *opaque, uint32_t addr, \
> +					       uint32_t value)		\
> + {									\
> +	 assigned_dev_region_t *r_access = (assigned_dev_region_t *)opaque; \
> +	 uint32_t r_pio = (unsigned long)r_access->r_virtbase		\
> +		 + (addr - r_access->e_physbase);			\
> +	 if (r_access->debug & DEVICE_ASSIGNMENT_DEBUG_PIO) {		\
> +		 fprintf(logfile, "assigned_dev_ioport_write" #suffix	\
> +			 ": r_pio=%08x e_physbase=%08x"			\
> +			 " r_virtbase=%08lx value=%08x\n", 		\
> +			 r_pio, (int)r_access->e_physbase,		\
> +			 (unsigned long)r_access->r_virtbase, value);	\
> +	 }								\
> +	 iopl(3);							\
> +	 out##suffix(value, r_pio);					\
> +  }
> +
> +assigned_dev_ioport_write(b)
> +assigned_dev_ioport_write(w)
> +assigned_dev_ioport_write(l)
> +
> +#define assigned_dev_ioport_read(suffix)				\
> + static uint32_t assigned_dev_ioport_read##suffix(void *opaque, uint32_t addr) \
> + {									\
> +	 assigned_dev_region_t *r_access = (assigned_dev_region_t *)opaque; \
> +	 uint32_t r_pio = (addr - r_access->e_physbase)			\
> +		 + (unsigned long)r_access->r_virtbase;			\

Please add iopl(3) here same as for the write case.
I think it was Sheng who mentioned that in his environment it was required.

We need to change this code in the future so that the iopls are not required, but for now we need to add this one too.

> +	 uint32_t value = in##suffix(r_pio);				\
> +	 if (r_access->debug & DEVICE_ASSIGNMENT_DEBUG_PIO) {		\
> +		 fprintf(logfile, "assigned_dev_ioport_read" #suffix	\
> +			 ": r_pio=%08x e_physbase=%08x r_virtbase=%08lx " \
> +			 "value=%08x\n", 				\
> +			 r_pio, (int)r_access->e_physbase, 		\
> +			 (unsigned long)r_access->r_virtbase, value);	\
> +	 }								\
> +	 return value;							\
> + }
> +
> +assigned_dev_ioport_read(b)
> +assigned_dev_ioport_read(w)
> +assigned_dev_ioport_read(l)
> +
> +static void assigned_dev_iomem_map(PCIDevice *pci_dev, int region_num,
> +			 uint32_t e_phys, uint32_t e_size, int type)
> +{
> +	assigned_dev_t *r_dev = (assigned_dev_t *) pci_dev;
> +	assigned_dev_region_t *region = &r_dev->v_addrs[region_num];
> +	int first_map = (region->e_size == 0);
> +	int ret = 0;
> +
> +	DEBUG("e_phys=%08x r_virt=%p type=%d len=%08x region_num=%d \n",
> +	      e_phys, r_dev->v_addrs[region_num].r_virtbase, type, e_size,
> +	      region_num);
> +
> +	region->e_physbase = e_phys;
> +	region->e_size = e_size;
> +
> +	if (!first_map)
> +		kvm_destroy_phys_mem(kvm_context, e_phys, e_size);
> +	if (e_size > 0)
> +		ret = kvm_register_userspace_phys_mem(kvm_context,
> +						      e_phys,
> +						      region->r_virtbase,
> +						      e_size,
> +						      0);
> +	if (ret != 0)
> +		fprintf(logfile, "%s: Error: create new mapping failed\n",
> +			__func__);
> +}
> +
> +static void assigned_dev_ioport_map(PCIDevice *pci_dev, int region_num,
> +				    uint32_t addr, uint32_t size, int type)
> +{
> +	assigned_dev_t *r_dev = (assigned_dev_t *) pci_dev;
> +	int i;
> +	uint32_t ((*rf[])(void *, uint32_t)) =
> +		{ assigned_dev_ioport_readb,
> +		  assigned_dev_ioport_readw,
> +		  assigned_dev_ioport_readl
> +		};
> +	void ((*wf[])(void *, uint32_t, uint32_t)) =
> +		{ assigned_dev_ioport_writeb,
> +		  assigned_dev_ioport_writew,
> +		  assigned_dev_ioport_writel
> +		};
> +
> +	r_dev->v_addrs[region_num].e_physbase = addr;
> +	DEBUG("%s: address=0x%x type=0x%x len=%d region_num=%d \n",
> +	      __func__, addr, type, size, region_num);
> +
> +	for (i = 0; i < 3; i++) {
> +		register_ioport_write(addr, size, 1<<i, wf[i],
> +				      (void *) (r_dev->v_addrs + region_num));
> +		register_ioport_read(addr, size, 1<<i, rf[i],
> +				     (void *) (r_dev->v_addrs + region_num));
> +	}
> +}
> +
> +static void assigned_dev_pci_write_config(PCIDevice *d, uint32_t address,
> +					  uint32_t val, int len)
> +{
> +	int fd, r;
> +
> +	DEBUG("%s: (%x.%x): address=%04x val=0x%08x len=%d\n",
> +	      __func__, ((d->devfn >> 3) & 0x1F), (d->devfn & 0x7),
> +	      (uint16_t) address, val, len);
> +
> +	if (address == 0x4)
> +		pci_default_write_config(d, address, val, len);
> +
> +	if ((address >= 0x10 && address <= 0x24) || address == 0x34 ||
> +	    address == 0x3c || address == 0x3d) {
> +		/* used for update-mappings (BAR emulation) */
> +		pci_default_write_config(d, address, val, len);
> +		return;
> +	}
> +	DEBUG("%s: NON BAR (%x.%x): address=%04x val=0x%08x len=%d\n",
> +	      __func__, ((d->devfn >> 3) & 0x1F), (d->devfn & 0x7),
> +	      (uint16_t) address, val, len);
> +	fd = ((assigned_dev_t *)d)->real_device.config_fd;
> +	lseek(fd, address, SEEK_SET);
> +again:
> +	r = write(fd, &val, len);
> +	if (r < 0) {
> +		if (errno == EINTR || errno == EAGAIN)
> +			goto again;
> +		fprintf(stderr, "%s: write failed, errno = %d\n",
> +			__func__, errno);
> +	}
> +}
> +
> +static uint32_t assigned_dev_pci_read_config(PCIDevice *d, uint32_t address,
> +					     int len)
> +{
> +	uint32_t val = 0;
> +	int fd, r;
> +
> +	if ((address >= 0x10 && address <= 0x24) || address == 0x34 ||
> +	    address == 0x3c || address == 0x3d) {
> +		val = pci_default_read_config(d, address, len);
> +		DEBUG("(%x.%x): address=%04x val=0x%08x len=%d\n",
> +		      (d->devfn >> 3) & 0x1F, (d->devfn & 0x7), address, val,
> +		      len);
> +		return val;
> +	}
> +
> +	/* vga specific, remove later */
> +	if (address == 0xFC)
> +		goto do_log;
> +
> +	fd = ((assigned_dev_t *)d)->real_device.config_fd;
> +	lseek(fd, address, SEEK_SET);
> +again:
> +	r = read(fd, &val, len);
> +	if (r < 0) {
> +		if (errno == EINTR || errno == EAGAIN)
> +			goto again;
> +		fprintf(stderr, "%s: read failed, errno = %d\n",
> +			__func__, errno);
> +	}
> +do_log:
> +	DEBUG("(%x.%x): address=%04x val=0x%08x len=%d\n",
> +	      (d->devfn >> 3) & 0x1F, (d->devfn & 0x7), address, val, len);
> +
> +	/* kill the special capabilities */
> +	if (address == 4 && len == 4)
> +		val &= ~0x100000;
> +	else if (address == 6)
> +		val &= ~0x10;
> +
> +	return val;
> +}
> +
> +static int assigned_dev_register_regions(pci_region_t *io_regions,
> +					 unsigned long regions_num,
> +					 assigned_dev_t *pci_dev)
> +{
> +	uint32_t i;
> +	pci_region_t *cur_region = io_regions;
> +
> +	for (i = 0; i < regions_num; i++, cur_region++) {
> +		if (!cur_region->valid)
> +			continue;
> +#ifdef DEVICE_ASSIGNMENT_DEBUG
> +		pci_dev->v_addrs[i].debug |= DEVICE_ASSIGNMENT_DEBUG_MMIO
> +					     | DEVICE_ASSIGNMENT_DEBUG_PIO;
> +#endif
> +		pci_dev->v_addrs[i].num = i;
> +
> +		/* handle memory io regions */
> +		if (cur_region->type & IORESOURCE_MEM) {
> +			int t = cur_region->type & IORESOURCE_PREFETCH
> +				? PCI_ADDRESS_SPACE_MEM_PREFETCH
> +				: PCI_ADDRESS_SPACE_MEM;
> +
> +			/* map physical memory */
> +			pci_dev->v_addrs[i].e_physbase = cur_region->base_addr;
> +			pci_dev->v_addrs[i].r_virtbase =
> +				mmap(NULL,
> +				     (cur_region->size + 0xFFF) & 0xFFFFF000,
> +				     PROT_WRITE | PROT_READ, MAP_SHARED,
> +				     cur_region->resource_fd, (off_t) 0);
> +
> +			if ((void *) -1 == pci_dev->v_addrs[i].r_virtbase) {
> +				fprintf(stderr, "%s: Error: Couldn't mmap 0x%x!"
> +					"\n", __func__,
> +					(uint32_t) (cur_region->base_addr));
> +				return -1;
> +			}
> +			pci_dev->v_addrs[i].r_size = cur_region->size;
> +			pci_dev->v_addrs[i].e_size = 0;
> +
> +			/* add offset */
> +			pci_dev->v_addrs[i].r_virtbase +=
> +				(cur_region->base_addr & 0xFFF);
> +
> +			pci_register_io_region((PCIDevice *) pci_dev, i,
> +					       cur_region->size, t,
> +					       assigned_dev_iomem_map);
> +			continue;
> +		}
> +		/* handle port io regions */
> +		pci_register_io_region((PCIDevice *) pci_dev, i,
> +				       cur_region->size, PCI_ADDRESS_SPACE_IO,
> +				       assigned_dev_ioport_map);
> +
> +		pci_dev->v_addrs[i].e_physbase = cur_region->base_addr;
> +		pci_dev->v_addrs[i].r_virtbase =
> +			(void *)(long)cur_region->base_addr;
> +		/* not relevant for port io */
> +		pci_dev->v_addrs[i].memory_index = 0;
> +	}
> +
> +	/* success */
> +	return 0;
> +}
> +
> +static int get_real_device(assigned_dev_t *pci_dev, uint8_t r_bus,
> +			   uint8_t r_dev, uint8_t r_func)
> +{
> +	char dir[128], name[128], comp[16];
> +	int fd, r = 0;
> +	FILE *f;
> +	unsigned long long start, end, size, flags;
> +	pci_region_t *rp;
> +	pci_dev_t *dev = &pci_dev->real_device;
> +
> +	dev->region_number = 0;
> +
> +	sprintf(dir, "/sys/bus/pci/devices/0000:%02x:%02x.%x/",
> +		r_bus, r_dev, r_func);
> +	strcpy(name, dir);
> +	strcat(name, "config");
> +	fd = open(name, O_RDWR);
> +	if (fd == -1) {
> +		fprintf(stderr, "%s: %s: %m\n", __func__, name);
> +		return 1;
> +	}
> +	dev->config_fd = fd;
> +again:
> +	r = read(fd, pci_dev->dev.config, sizeof pci_dev->dev.config);
> +	if (r < 0) {
> +		if (errno == EINTR || errno == EAGAIN)
> +			goto again;
> +		fprintf(stderr, "%s: read failed, errno = %d\n",
> +			__func__, errno);
> +	}
> +	strcpy(name, dir);
> +	strcat(name, "resource");
> +
> +	f = fopen(name, "r");
> +	if (f == NULL) {
> +		fprintf(stderr, "%s: %s: %m\n", __func__, name);
> +		return 1;
> +	}
> +	for (r = 0; fscanf(f, "%lli %lli %lli\n", &start, &end, &flags) == 3;
> +	     r++) {
> +		rp = dev->regions + r;
> +		rp->valid = 0;
> +		size = end - start + 1;
> +		flags &= IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH;
> +		if (size == 0 || (flags & ~IORESOURCE_PREFETCH) == 0)
> +			continue;
> +		if (flags & IORESOURCE_MEM) {
> +			flags &= ~IORESOURCE_IO;
> +			sprintf(comp, "resource%d", r);
> +			strcpy(name, dir);
> +			strcat(name, comp);
> +			fd = open(name, O_RDWR);
> +			if (fd == -1)
> +				continue;		/* probably ROM */
> +			rp->resource_fd = fd;
> +		} else
> +			flags &= ~IORESOURCE_PREFETCH;
> +
> +		rp->type = flags;
> +		rp->valid = 1;
> +		rp->base_addr = start;
> +		rp->size = size;
> +		DEBUG("%s: region %d size %d start 0x%x type %d "
> +		      "resource_fd %d\n", __func__, r, rp->size, start,
> +		      rp->type, rp->resource_fd);
> +	}
> +	fclose(f);
> +
> +	dev->region_number = r;
> +	return 0;
> +}
> +
> +static uint32_t calc_assigned_dev_id(uint8_t bus, uint8_t devfn)
> +{
> +	return (uint32_t)bus << 8 | (uint32_t)devfn;
> +}
> +
> +static assigned_dev_t *register_real_device(PCIBus *e_bus,
> +					    const char *e_dev_name,
> +					    int e_devfn, uint8_t r_bus,
> +					    uint8_t r_dev, uint8_t r_func,
> +					    int flags)
> +{
> +	int rc;
> +	assigned_dev_t *pci_dev;
> +	uint8_t e_device, e_intx;
> +
> +	DEBUG("%s: Registering real physical device %s (devfn=0x%x)\n",
> +	      __func__, e_dev_name, e_devfn);
> +
> +	pci_dev = (assigned_dev_t *)
> +		pci_register_device(e_bus, e_dev_name, sizeof(assigned_dev_t),
> +				    e_devfn, assigned_dev_pci_read_config,
> +				    assigned_dev_pci_write_config);
> +	if (NULL == pci_dev) {
> +		fprintf(stderr, "%s: Error: Couldn't register real device %s\n",
> +			__func__, e_dev_name);
> +		return NULL;
> +	}
> +	if (get_real_device(pci_dev, r_bus, r_dev, r_func)) {
> +		fprintf(stderr, "%s: Error: Couldn't get real device (%s)!\n",
> +			__func__, e_dev_name);
> +		goto out;
> +	}
> +
> +	/* handle real device's MMIO/PIO BARs */
> +	if (assigned_dev_register_regions(pci_dev->real_device.regions,
> +					  pci_dev->real_device.region_number,
> +					  pci_dev))
> +		goto out;
> +
> +	/* handle interrupt routing */
> +	e_device = (pci_dev->dev.devfn >> 3) & 0x1f;
> +	e_intx = pci_dev->dev.config[0x3d] - 1;
> +	pci_dev->intpin = e_intx;
> +	pci_dev->run = 0;
> +	pci_dev->girq = 0;
> +	pci_dev->h_busnr = r_bus;
> +	pci_dev->h_devfn = PCI_DEVFN(r_dev, r_func);
> +
> +#ifdef KVM_CAP_DEVICE_ASSIGNMENT
> +	if (kvm_enabled()) {
> +		struct kvm_assigned_pci_dev assigned_dev_data;
> +
> +		memset(&assigned_dev_data, 0, sizeof(assigned_dev_data));
> +		assigned_dev_data.assigned_dev_id  =
> +			calc_assigned_dev_id(pci_dev->h_busnr,
> +					     (uint32_t)pci_dev->h_devfn);
> +		assigned_dev_data.busnr = pci_dev->h_busnr;
> +		assigned_dev_data.devfn = pci_dev->h_devfn;
> +		assigned_dev_data.flags = flags;
> +		rc = kvm_assign_pci_device(kvm_context,
> +					   &assigned_dev_data);
> +		if (rc < 0) {
> +			fprintf(stderr, "Could not notify kernel about "
> +				"assigned device \"%s\"\n", e_dev_name);
> +			perror("pt-ioctl");
> +			goto out;
> +		}
> +	}
> +#endif
> +	fprintf(logfile, "Registered host PCI device %02x:%02x.%1x "
> +		"(\"%s\") as guest device %02x:%02x.%1x\n",
> +		r_bus, r_dev, r_func, e_dev_name,
> +		pci_bus_num(e_bus), e_device, r_func);
> +
> +	return pci_dev;
> +out:
> +	pci_unregister_device(&pci_dev->dev);
> +	return NULL;
> +}
> +
> +#define	MAX_ASSIGNED_DEVS 4
> +struct {
> +	char name[15];
> +	int bus;
> +	int dev;
> +	int func;
> +	int dma;
> +	assigned_dev_t *assigned_dev;
> +} assigned_devices[MAX_ASSIGNED_DEVS];
> +
> +int nr_assigned_devices;
> +extern int get_param_value(char *buf, int buf_size,
> +			   const char *tag, const char *str);
> +extern int piix_get_irq(int);
> +
> +#ifdef KVM_CAP_DEVICE_ASSIGNMENT
> +/* The pci config space got updated. Check if irq numbers have changed
> + * for our devices
> + */
> +void assigned_dev_update_irq(PCIDevice *d)
> +{
> +	int i, irq, r;
> +	assigned_dev_t *assigned_dev;
> +
> +	for (i = 0; i < nr_assigned_devices; i++) {
> +		assigned_dev = assigned_devices[i].assigned_dev;
> +		if (assigned_dev == NULL)
> +			continue;
> +
> +		irq = pci_map_irq(&assigned_dev->dev, assigned_dev->intpin);
> +		irq = piix_get_irq(irq);
> +
> +		if (irq != assigned_dev->girq) {
> +			struct kvm_assigned_irq assigned_irq_data;
> +
> +			memset(&assigned_irq_data, 0, sizeof assigned_irq_data);
> +			assigned_irq_data.assigned_dev_id  =
> +				calc_assigned_dev_id(assigned_dev->h_busnr,
> +						     (uint8_t)
> +						     assigned_dev->h_devfn);
> +			assigned_irq_data.guest_irq = irq;
> +			assigned_irq_data.host_irq =
> +				assigned_dev->real_device.irq;
> +			r = kvm_assign_irq(kvm_context, &assigned_irq_data);
> +			if (r < 0) {
> +				perror("assigned_dev_update_irq");
> +				pci_unregister_device(&assigned_dev->dev);
> +				continue;
> +			}
> +			assigned_dev->girq = irq;
> +		}
> +	}
> +}
> +#endif
> +
> +static int init_device_assignment(void)
> +{
> +	/* Do we have any devices to be assigned? */
> +	if (nr_assigned_devices == 0)
> +		return -1;
> +	iopl(3);
> +	return 0;
> +}
> +
> +int init_assigned_device(PCIBus *bus, int *index)
> +{
> +	assigned_dev_t *dev = NULL;
> +	int i, ret = 0;
> +
> +	if (*index == -1) {
> +		if (init_device_assignment() < 0)
> +			return -1;
> +
> +		*index = nr_assigned_devices - 1;
> +	}
> +	i = *index;
> +	dev = register_real_device(bus, assigned_devices[i].name, -1,
> +				   assigned_devices[i].bus,
> +				   assigned_devices[i].dev,
> +				   assigned_devices[i].func,
> +				   assigned_devices[i].dma);
> +	if (dev == NULL) {
> +		fprintf(stderr, "Error: Couldn't register device \"%s\"\n",
> +			assigned_devices[i].name);
> +		ret = -1;
> +	}
> +	assigned_devices[i].assigned_dev = dev;
> +
> +	--*index;
> +	return ret;
> +}
> +
> +/*
> + * Syntax to assign device:
> + *
> + * -pcidevice dev=bus:dev.func,dma=dma
> + *
> + * Example:
> + * -pcidevice dev=00:13.0,dma=pvdma
> + *
> + * dma can currently be 'none' to disable iommu support.
> + */
> +void add_assigned_device(const char *arg)
> +{
> +	char *cp, *cp1;
> +	char device[8];
> +	char dma[6];
> +	int r;
> +
> +	if (nr_assigned_devices >= MAX_ASSIGNED_DEVS) {
> +		fprintf(stderr, "Too many assigned devices (max %d)\n",
> +			MAX_ASSIGNED_DEVS);
> +		return;
> +	}
> +	memset(&assigned_devices[nr_assigned_devices], 0,
> +	       sizeof assigned_devices[nr_assigned_devices]);
> +
> +	r = get_param_value(device, sizeof device, "host", arg);
> +
> +	r = get_param_value(assigned_devices[nr_assigned_devices].name,
> +			    sizeof assigned_devices[nr_assigned_devices].name,
> +			    "name", arg);
> +	if (!r)
> +		strncpy(assigned_devices[nr_assigned_devices].name, device, 8);
> +
> +#ifdef KVM_CAP_IOMMU
> +	r = kvm_check_extension(kvm_context, KVM_CAP_IOMMU);

This code is called during parsing of the parameters and at this time we
do not have valid kvm->fd in libkvm so its not going to work.

Regards,
Ben

Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Muli Ben-Yehuda]

On Wed, Aug 27, 2008 at 03:48:54PM +0300, Ben-Ami Yassour1 wrote:

> On Tue, 2008-08-26 at 18:29 +0300, Amit Shah wrote:

> > From: Or Sagi <ors@tutis.com>
> > From: Nir Peleg <nir@tutis.com>
> > From: Amit Shah <amit.shah@qumranet.com>
> > From: Ben-Ami Yassour <benami@il.ibm.com>
> > From: Glauber de Oliveira Costa <gcosta@redhat.com>

Hey Amit,

In addition to Ben's other comments, note that git only uses the first
From: line as the author of the patch, and the rest are meaningless
from git's point of view. With a patch such as this where there were
multiple authors, I would pick one person (whoever wrote the bulk of
the patch) as the author, and then acknowledge the rest in the
changelog comment, "based on a patch by ...", etc.

Also, if that person's patch had a Signed-off by, you should include
that too. Or at least that's how I understand it.

Cheers,
Muli
-- 
Workshop on I/O Virtualization (WIOV '08)
Co-located with OSDI '08, Dec 2008, San Diego, CA
http://www.usenix.org/wiov08

Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devicesto guests

[Amit Shah]

* On Wednesday 27 Aug 2008 19:16:40 Muli Ben-Yehuda wrote:
> On Wed, Aug 27, 2008 at 03:48:54PM +0300, Ben-Ami Yassour1 wrote:
> > On Tue, 2008-08-26 at 18:29 +0300, Amit Shah wrote:
> > > From: Or Sagi <ors@tutis.com>
> > > From: Nir Peleg <nir@tutis.com>
> > > From: Amit Shah <amit.shah@qumranet.com>
> > > From: Ben-Ami Yassour <benami@il.ibm.com>
> > > From: Glauber de Oliveira Costa <gcosta@redhat.com>
>
> Hey Amit,
>
> In addition to Ben's other comments, note that git only uses the first
> From: line as the author of the patch, and the rest are meaningless
> from git's point of view. With a patch such as this where there were

That's right; this is just a way to mention authorship (instead of based on..)

> multiple authors, I would pick one person (whoever wrote the bulk of
> the patch) as the author, and then acknowledge the rest in the
> changelog comment, "based on a patch by ...", etc.
>
> Also, if that person's patch had a Signed-off by, you should include
> that too. Or at least that's how I understand it.

I won't say so. Let's say X sends a patch which Y picks up and add changes 
which X doesn't approve or can't ascertain the source of (Y could have copied 
them from somewhere else). It should just contain Y's sign-off.

The Sign-off was introduced to trace the flow of patches from individual 
authors to people forwarding them onwards. If something is found to be wrong 
with a patch that was submitted, the person listed first in the Signed-off-by 
series will be held accountable.

Amit

Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devicesto guests

[Amit Shah]

* On Wednesday 27 Aug 2008 18:18:54 Ben-Ami Yassour wrote:
> On Tue, 2008-08-26 at 18:29 +0300, Amit Shah wrote:

> > +#define assigned_dev_ioport_read(suffix)				\
> > + static uint32_t assigned_dev_ioport_read##suffix(void *opaque, uint32_t
> > addr) \ + {									\
> > +	 assigned_dev_region_t *r_access = (assigned_dev_region_t *)opaque; \
> > +	 uint32_t r_pio = (addr - r_access->e_physbase)			\
> > +		 + (unsigned long)r_access->r_virtbase;			\
>
> Please add iopl(3) here same as for the write case.
> I think it was Sheng who mentioned that in his environment it was required.

OK.

> We need to change this code in the future so that the iopls are not
> required, but for now we need to add this one too.

Right.

> > +void add_assigned_device(const char *arg)
> > +{
> > +	char *cp, *cp1;
> > +	char device[8];
> > +	char dma[6];
> > +	int r;
> > +
> > +	if (nr_assigned_devices >= MAX_ASSIGNED_DEVS) {
> > +		fprintf(stderr, "Too many assigned devices (max %d)\n",
> > +			MAX_ASSIGNED_DEVS);
> > +		return;
> > +	}
> > +	memset(&assigned_devices[nr_assigned_devices], 0,
> > +	       sizeof assigned_devices[nr_assigned_devices]);
> > +
> > +	r = get_param_value(device, sizeof device, "host", arg);
> > +
> > +	r = get_param_value(assigned_devices[nr_assigned_devices].name,
> > +			    sizeof assigned_devices[nr_assigned_devices].name,
> > +			    "name", arg);
> > +	if (!r)
> > +		strncpy(assigned_devices[nr_assigned_devices].name, device, 8);
> > +
> > +#ifdef KVM_CAP_IOMMU
> > +	r = kvm_check_extension(kvm_context, KVM_CAP_IOMMU);
>
> This code is called during parsing of the parameters and at this time we
> do not have valid kvm->fd in libkvm so its not going to work.

You're right; I updated this to happen when assigning the device (ioctl-time)

Amit

Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Anthony Liguori]

Hi Amit,

Amit Shah wrote:
> With this patch, we can assign a device on the host machine to a
> guest.
>
> A new command-line option, -pcidevice is added.
> For example, to invoke it for a device sitting at PCI bus:dev.fn
> 04:08.0 with host IRQ 18, use this:
>
> 	-pcidevice host=04:08.0
>   

Let's make sure it also works via hotplug.  We already have a pci_add 
command.  I would expect the syntax should be host:04:08.0 to be more in 
line with usb.

> The host driver for the device, if any, is to be removed before
> assigning the device.
>
> This works only with the in-kernel irqchip method; to use the
> userspace irqchip, a kernel module (irqhook) and some extra changes
> are needed.
>
> Signed-off-by: Amit Shah <amit.shah@qumranet.com>
> ---
>  libkvm/libkvm-x86.c         |   14 +
>  libkvm/libkvm.h             |   27 ++
>  qemu/Makefile.target        |    1 +
>  qemu/hw/device-assignment.c |  600 +++++++++++++++++++++++++++++++++++++++++++
>  qemu/hw/device-assignment.h |   94 +++++++
>  qemu/hw/isa.h               |    2 +
>  qemu/hw/pc.c                |    9 +
>  qemu/hw/pci.c               |   12 +
>  qemu/hw/pci.h               |    1 +
>  qemu/hw/piix_pci.c          |   19 ++
>  qemu/vl.c                   |   18 ++
>  11 files changed, 797 insertions(+), 0 deletions(-)
>  create mode 100644 qemu/hw/device-assignment.c
>  create mode 100644 qemu/hw/device-assignment.h
>   

This patch is too big on it's on.  It should be split into logical parts.

> diff --git a/qemu/Makefile.target b/qemu/Makefile.target
> index 2332fe3..750ecd5 100644
> --- a/qemu/Makefile.target
> +++ b/qemu/Makefile.target
> @@ -611,6 +611,7 @@ OBJS+= ide.o pckbd.o ps2.o vga.o $(SOUND_HW) dma.o
>  OBJS+= fdc.o mc146818rtc.o serial.o i8259.o i8254.o pcspk.o pc.o
>  OBJS+= cirrus_vga.o apic.o parallel.o acpi.o piix_pci.o
>  OBJS+= usb-uhci.o vmmouse.o vmport.o vmware_vga.o extboot.o
> +OBJS+= device-assignment.o
>   

We should conditionally compile this into qemu only if we know we can 
support it (has to be a Linux host for instance).

>  ifeq ($(USE_KVM_PIT), 1)
>  OBJS+= i8254-kvm.o
>  endif
> diff --git a/qemu/hw/device-assignment.c b/qemu/hw/device-assignment.c
> new file mode 100644
> index 0000000..8bc4e5c
> --- /dev/null
> +++ b/qemu/hw/device-assignment.c
> @@ -0,0 +1,600 @@
> +/*
> + * Copyright (c) 2007, Neocleus Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
> + * Place - Suite 330, Boston, MA 02111-1307 USA.
> + *
> + *
> + *  Assign a PCI device from the host to a guest VM.
> + *
> + *  Adapted for KVM by Qumranet.
> + *
> + *  Copyright (c) 2007, Neocleus, Alex Novik (alex@neocleus.com)
> + *  Copyright (c) 2007, Neocleus, Guy Zana (guy@neocleus.com)
> + *  Copyright (C) 2008, Qumranet, Amit Shah (amit.shah@qumranet.com)
> + */
> +#include <stdio.h>
> +#include <pthread.h>
>   

Why is pthread being included?

> +#include <sys/io.h>
> +#include <sys/ioctl.h>
> +#include <linux/types.h>
> +
> +/* From linux/ioport.h */
> +#define IORESOURCE_IO		0x00000100	/* Resource type */
> +#define IORESOURCE_MEM		0x00000200
> +#define IORESOURCE_IRQ		0x00000400
> +#define IORESOURCE_DMA		0x00000800
> +#define IORESOURCE_PREFETCH	0x00001000	/* No side effects */
> +
> +#include "device-assignment.h"
> +#include "irq.h"
> +
> +#include "qemu-kvm.h"
> +#include <linux/kvm_para.h>
> +
> +extern FILE *logfile;
> +
> +/* #define DEVICE_ASSIGNMENT_DEBUG */
> +
> +#ifdef DEVICE_ASSIGNMENT_DEBUG
> +#define DEBUG(fmt, args...) fprintf(stderr, "%s: " fmt, __func__ , ## args)
> +#else
> +#define DEBUG(fmt, args...)
> +#endif
> +
> +#define assigned_dev_ioport_write(suffix)				\
> + static void assigned_dev_ioport_write##suffix(void *opaque, uint32_t addr, \
> +					       uint32_t value)		\
> + {									\
> +	 assigned_dev_region_t *r_access = (assigned_dev_region_t *)opaque; \
> +	 uint32_t r_pio = (unsigned long)r_access->r_virtbase		\
> +		 + (addr - r_access->e_physbase);			\
> +	 if (r_access->debug & DEVICE_ASSIGNMENT_DEBUG_PIO) {		\
> +		 fprintf(logfile, "assigned_dev_ioport_write" #suffix	\
> +			 ": r_pio=%08x e_physbase=%08x"			\
> +			 " r_virtbase=%08lx value=%08x\n", 		\
> +			 r_pio, (int)r_access->e_physbase,		\
> +			 (unsigned long)r_access->r_virtbase, value);	\
> +	 }								\
> +	 iopl(3);							\
> +	 out##suffix(value, r_pio);					\
> +  }
> +
> +assigned_dev_ioport_write(b)
> +assigned_dev_ioport_write(w)
> +assigned_dev_ioport_write(l)
>   

Please don't do this sort of trickery with macros.  Also don't write to 
logfile, write to stderr.  Debug should follow the same style as the 
rest of the code.

Also, this whole file needs to be reformated to the QEMU style.  How far 
has this diverged from the Xen version of the code?  If it's 
sufficiently close, we should coordinate with those guys such that this 
code can eventually go upstream.

> +
> +static void assigned_dev_iomem_map(PCIDevice *pci_dev, int region_num,
> +			 uint32_t e_phys, uint32_t e_size, int type)
> +{
> +	assigned_dev_t *r_dev = (assigned_dev_t *) pci_dev;
> +	assigned_dev_region_t *region = &r_dev->v_addrs[region_num];
> +	int first_map = (region->e_size == 0);
> +	int ret = 0;
> +
> +	DEBUG("e_phys=%08x r_virt=%p type=%d len=%08x region_num=%d \n",
> +	      e_phys, r_dev->v_addrs[region_num].r_virtbase, type, e_size,
> +	      region_num);
> +
> +	region->e_physbase = e_phys;
> +	region->e_size = e_size;
> +
> +	if (!first_map)
> +		kvm_destroy_phys_mem(kvm_context, e_phys, e_size);
>   

We try to avoid open coding calls to libkvm functions directly within 
QEMU.  At the least, it should be wrapped with an if (kvm_enabled()).
> +static void assigned_dev_ioport_map(PCIDevice *pci_dev, int region_num,
> +				    uint32_t addr, uint32_t size, int type)
> +{
> +	assigned_dev_t *r_dev = (assigned_dev_t *) pci_dev;
> +	int i;
> +	uint32_t ((*rf[])(void *, uint32_t)) =
> +		{ assigned_dev_ioport_readb,
> +		  assigned_dev_ioport_readw,
> +		  assigned_dev_ioport_readl
> +		};
> +	void ((*wf[])(void *, uint32_t, uint32_t)) =
> +		{ assigned_dev_ioport_writeb,
> +		  assigned_dev_ioport_writew,
> +		  assigned_dev_ioport_writel
> +		};
>   

I don't think this any nicer (and certainly not less lines) than just 
open coding the register_ioport_{read,write} calls.

> +	r_dev->v_addrs[region_num].e_physbase = addr;
> +	DEBUG("%s: address=0x%x type=0x%x len=%d region_num=%d \n",
> +	      __func__, addr, type, size, region_num);
> +
> +	for (i = 0; i < 3; i++) {
> +		register_ioport_write(addr, size, 1<<i, wf[i],
> +				      (void *) (r_dev->v_addrs + region_num));
> +		register_ioport_read(addr, size, 1<<i, rf[i],
> +				     (void *) (r_dev->v_addrs + region_num));
> +	}
> +}
> +
> +static void assigned_dev_pci_write_config(PCIDevice *d, uint32_t address,
> +					  uint32_t val, int len)
> +{
> +	int fd, r;
> +
> +	DEBUG("%s: (%x.%x): address=%04x val=0x%08x len=%d\n",
> +	      __func__, ((d->devfn >> 3) & 0x1F), (d->devfn & 0x7),
> +	      (uint16_t) address, val, len);
> +
> +	if (address == 0x4)
> +		pci_default_write_config(d, address, val, len);
> +
> +	if ((address >= 0x10 && address <= 0x24) || address == 0x34 ||
> +	    address == 0x3c || address == 0x3d) {
> +		/* used for update-mappings (BAR emulation) */
> +		pci_default_write_config(d, address, val, len);
> +		return;
> +	}
>   

Is this first if check correct?  It calls pci_default_write_config but 
then doesn't return?  This definitely needs a comment.

> +	DEBUG("%s: NON BAR (%x.%x): address=%04x val=0x%08x len=%d\n",
> +	      __func__, ((d->devfn >> 3) & 0x1F), (d->devfn & 0x7),
> +	      (uint16_t) address, val, len);
> +	fd = ((assigned_dev_t *)d)->real_device.config_fd;
>   

assigned_dev_t is not QEMU style.  It should be AssignedDevice or 
something similar.

> +	lseek(fd, address, SEEK_SET);
>   

Needs error checking.

I'm not going to go any further for now.  The code needs an awful lot of 
cleanup.  Please try to do at least a couple passes of cleanup and post 
again.

Regards,

Anthony Liguori

Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Anthony Liguori]

Anthony Liguori wrote:
> Hi Amit,
>
>>  ifeq ($(USE_KVM_PIT), 1)
>>  OBJS+= i8254-kvm.o
>>  endif
>> diff --git a/qemu/hw/device-assignment.c b/qemu/hw/device-assignment.c
>> new file mode 100644
>> index 0000000..8bc4e5c
>> --- /dev/null
>> +++ b/qemu/hw/device-assignment.c

Where did this come from originally?  It's completely different from 
what is in xen-unstable.  What's in xen-unstable is actually a lot nicer 
IMHO.

Regards,

Anthony Liguori

Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Ian Jackson]

Anthony Liguori writes ("Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests"):
> Where did this come from originally?  It's completely different from 
> what is in xen-unstable.  What's in xen-unstable is actually a lot nicer 
> IMHO.

Amit: have you taken a look at the code in the qemu-xen tree ?
It might be worth seeing if some of that could be shared.

Ian.

Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Amit Shah]

Hello Ian,

* On Wednesday 27 Aug 2008 19:50:12 Ian Jackson wrote:
> Anthony Liguori writes ("Re: [PATCH 1/1] KVM/userspace: Support for 
assigning PCI devices to guests"):
> > Where did this come from originally?  It's completely different from
> > what is in xen-unstable.  What's in xen-unstable is actually a lot nicer
> > IMHO.
>
> Amit: have you taken a look at the code in the qemu-xen tree ?
> It might be worth seeing if some of that could be shared.

They are definitely based off the same code with a lot of things changing in 
the mean time in both the camps. The base still remains the same from a 
cursory glance.

Amit

Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Amit Shah]

* On Wednesday 27 Aug 2008 19:20:26 Anthony Liguori wrote:
> Hi Amit,
>
> Amit Shah wrote:
> > With this patch, we can assign a device on the host machine to a
> > guest.
> >
> > A new command-line option, -pcidevice is added.
> > For example, to invoke it for a device sitting at PCI bus:dev.fn
> > 04:08.0 with host IRQ 18, use this:
> >
> > 	-pcidevice host=04:08.0
>
> Let's make sure it also works via hotplug.  We already have a pci_add
> command.  I would expect the syntax should be host:04:08.0 to be more in
> line with usb.

I've not yet tested it (but based on your comments from last time, I made the 
necessary changes).

> >  libkvm/libkvm-x86.c         |   14 +
> >  libkvm/libkvm.h             |   27 ++
> >  qemu/Makefile.target        |    1 +
> >  qemu/hw/device-assignment.c |  600
> > +++++++++++++++++++++++++++++++++++++++++++ qemu/hw/device-assignment.h |
> >   94 +++++++
> >  qemu/hw/isa.h               |    2 +
> >  qemu/hw/pc.c                |    9 +
> >  qemu/hw/pci.c               |   12 +
> >  qemu/hw/pci.h               |    1 +
> >  qemu/hw/piix_pci.c          |   19 ++
> >  qemu/vl.c                   |   18 ++
> >  11 files changed, 797 insertions(+), 0 deletions(-)
> >  create mode 100644 qemu/hw/device-assignment.c
> >  create mode 100644 qemu/hw/device-assignment.h
>
> This patch is too big on it's on.  It should be split into logical parts.

However, it just adds device assignment support and does nothing else. I don't 
see a way of splitting this any more.

> > diff --git a/qemu/Makefile.target b/qemu/Makefile.target
> > index 2332fe3..750ecd5 100644
> > --- a/qemu/Makefile.target
> > +++ b/qemu/Makefile.target
> > @@ -611,6 +611,7 @@ OBJS+= ide.o pckbd.o ps2.o vga.o $(SOUND_HW) dma.o
> >  OBJS+= fdc.o mc146818rtc.o serial.o i8259.o i8254.o pcspk.o pc.o
> >  OBJS+= cirrus_vga.o apic.o parallel.o acpi.o piix_pci.o
> >  OBJS+= usb-uhci.o vmmouse.o vmport.o vmware_vga.o extboot.o
> > +OBJS+= device-assignment.o
>
> We should conditionally compile this into qemu only if we know we can
> support it (has to be a Linux host for instance).

Right now, it gets compiled only on x86. I'll see how to limit this further to 
Linux.

> > +#include <stdio.h>
> > +#include <pthread.h>
>
> Why is pthread being included?

Leftover; removed this and other unneeded #includes.

> > +#include <sys/io.h>
> > +#include <sys/ioctl.h>
> > +#include <linux/types.h>
> > +
> > +/* From linux/ioport.h */
> > +#define IORESOURCE_IO		0x00000100	/* Resource type */
> > +#define IORESOURCE_MEM		0x00000200
> > +#define IORESOURCE_IRQ		0x00000400
> > +#define IORESOURCE_DMA		0x00000800
> > +#define IORESOURCE_PREFETCH	0x00001000	/* No side effects */
> > +
> > +#include "device-assignment.h"
> > +#include "irq.h"
> > +
> > +#include "qemu-kvm.h"
> > +#include <linux/kvm_para.h>
> > +
> > +extern FILE *logfile;
> > +
> > +/* #define DEVICE_ASSIGNMENT_DEBUG */
> > +
> > +#ifdef DEVICE_ASSIGNMENT_DEBUG
> > +#define DEBUG(fmt, args...) fprintf(stderr, "%s: " fmt, __func__ , ##
> > args) +#else
> > +#define DEBUG(fmt, args...)
> > +#endif
> > +
> > +#define assigned_dev_ioport_write(suffix)				\
> > + static void assigned_dev_ioport_write##suffix(void *opaque, uint32_t
> > addr, \ +					       uint32_t value)		\
> > + {									\
> > +	 assigned_dev_region_t *r_access = (assigned_dev_region_t *)opaque; \
> > +	 uint32_t r_pio = (unsigned long)r_access->r_virtbase		\
> > +		 + (addr - r_access->e_physbase);			\
> > +	 if (r_access->debug & DEVICE_ASSIGNMENT_DEBUG_PIO) {		\
> > +		 fprintf(logfile, "assigned_dev_ioport_write" #suffix	\
> > +			 ": r_pio=%08x e_physbase=%08x"			\
> > +			 " r_virtbase=%08lx value=%08x\n", 		\
> > +			 r_pio, (int)r_access->e_physbase,		\
> > +			 (unsigned long)r_access->r_virtbase, value);	\
> > +	 }								\
> > +	 iopl(3);							\
> > +	 out##suffix(value, r_pio);					\
> > +  }
> > +
> > +assigned_dev_ioport_write(b)
> > +assigned_dev_ioport_write(w)
> > +assigned_dev_ioport_write(l)
>
> Please don't do this sort of trickery with macros.  Also don't write to
> logfile, write to stderr.  Debug should follow the same style as the
> rest of the code.

logfile is just #define logfile stderr. I removed it.

> Also, this whole file needs to be reformated to the QEMU style.  How far
> has this diverged from the Xen version of the code?  If it's
> sufficiently close, we should coordinate with those guys such that this
> code can eventually go upstream.

As you noticed, it's quite different. They have a lot more code in there. (3k+ 
lines vs 600 lines). I guess most of it went away when we realised we didn't 
need all that. Also, I noticed most of the code there is not in the qemu 
style.

> > +static void assigned_dev_iomem_map(PCIDevice *pci_dev, int region_num,
> > +			 uint32_t e_phys, uint32_t e_size, int type)
> > +{
> > +	assigned_dev_t *r_dev = (assigned_dev_t *) pci_dev;
> > +	assigned_dev_region_t *region = &r_dev->v_addrs[region_num];
> > +	int first_map = (region->e_size == 0);
> > +	int ret = 0;
> > +
> > +	DEBUG("e_phys=%08x r_virt=%p type=%d len=%08x region_num=%d \n",
> > +	      e_phys, r_dev->v_addrs[region_num].r_virtbase, type, e_size,
> > +	      region_num);
> > +
> > +	region->e_physbase = e_phys;
> > +	region->e_size = e_size;
> > +
> > +	if (!first_map)
> > +		kvm_destroy_phys_mem(kvm_context, e_phys, e_size);
>
> We try to avoid open coding calls to libkvm functions directly within
> QEMU.  At the least, it should be wrapped with an if (kvm_enabled()).

With the direct-mmio patch, we just start depending on KVM. Ben-Ami, is there 
a chance you can keep the MMIO-via-userspace method supported as well for 
non-kvm hosts?

> > +static void assigned_dev_ioport_map(PCIDevice *pci_dev, int region_num,
> > +				    uint32_t addr, uint32_t size, int type)
> > +{
> > +	assigned_dev_t *r_dev = (assigned_dev_t *) pci_dev;
> > +	int i;
> > +	uint32_t ((*rf[])(void *, uint32_t)) =
> > +		{ assigned_dev_ioport_readb,
> > +		  assigned_dev_ioport_readw,
> > +		  assigned_dev_ioport_readl
> > +		};
> > +	void ((*wf[])(void *, uint32_t, uint32_t)) =
> > +		{ assigned_dev_ioport_writeb,
> > +		  assigned_dev_ioport_writew,
> > +		  assigned_dev_ioport_writel
> > +		};
>
> I don't think this any nicer (and certainly not less lines) than just
> open coding the register_ioport_{read,write} calls.

Sure.

> > +	r_dev->v_addrs[region_num].e_physbase = addr;
> > +	DEBUG("%s: address=0x%x type=0x%x len=%d region_num=%d \n",
> > +	      __func__, addr, type, size, region_num);
> > +
> > +	for (i = 0; i < 3; i++) {
> > +		register_ioport_write(addr, size, 1<<i, wf[i],
> > +				      (void *) (r_dev->v_addrs + region_num));
> > +		register_ioport_read(addr, size, 1<<i, rf[i],
> > +				     (void *) (r_dev->v_addrs + region_num));
> > +	}
> > +}
> > +
> > +static void assigned_dev_pci_write_config(PCIDevice *d, uint32_t
> > address, +					  uint32_t val, int len)
> > +{
> > +	int fd, r;
> > +
> > +	DEBUG("%s: (%x.%x): address=%04x val=0x%08x len=%d\n",
> > +	      __func__, ((d->devfn >> 3) & 0x1F), (d->devfn & 0x7),
> > +	      (uint16_t) address, val, len);
> > +
> > +	if (address == 0x4)
> > +		pci_default_write_config(d, address, val, len);
> > +
> > +	if ((address >= 0x10 && address <= 0x24) || address == 0x34 ||
> > +	    address == 0x3c || address == 0x3d) {
> > +		/* used for update-mappings (BAR emulation) */
> > +		pci_default_write_config(d, address, val, len);
> > +		return;
> > +	}
>
> Is this first if check correct?  It calls pci_default_write_config but
> then doesn't return?  This definitely needs a comment.
>
> > +	DEBUG("%s: NON BAR (%x.%x): address=%04x val=0x%08x len=%d\n",
> > +	      __func__, ((d->devfn >> 3) & 0x1F), (d->devfn & 0x7),
> > +	      (uint16_t) address, val, len);
> > +	fd = ((assigned_dev_t *)d)->real_device.config_fd;
>
> assigned_dev_t is not QEMU style.  It should be AssignedDevice or
> something similar.

Will change this.

> > +	lseek(fd, address, SEEK_SET);
>
> Needs error checking.
>
> I'm not going to go any further for now.  The code needs an awful lot of
> cleanup.  Please try to do at least a couple passes of cleanup and post
> again.

From your other mail:

> Where did this come from originally?  It's completely different from
> what is in xen-unstable.  What's in xen-unstable is actually a lot nicer
> IMHO.

Nicer in what way?

I think the original code was picked up from before the time it was merged in 
Xen.

Amit

Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Anthony Liguori]

Amit Shah wrote:
> * On Wednesday 27 Aug 2008 19:20:26 Anthony Liguori wrote:
>   
>
>>>  libkvm/libkvm-x86.c         |   14 +
>>>  libkvm/libkvm.h             |   27 ++
>>>  qemu/Makefile.target        |    1 +
>>>  qemu/hw/device-assignment.c |  600
>>> +++++++++++++++++++++++++++++++++++++++++++ qemu/hw/device-assignment.h |
>>>   94 +++++++
>>>  qemu/hw/isa.h               |    2 +
>>>  qemu/hw/pc.c                |    9 +
>>>  qemu/hw/pci.c               |   12 +
>>>  qemu/hw/pci.h               |    1 +
>>>  qemu/hw/piix_pci.c          |   19 ++
>>>  qemu/vl.c                   |   18 ++
>>>  11 files changed, 797 insertions(+), 0 deletions(-)
>>>  create mode 100644 qemu/hw/device-assignment.c
>>>  create mode 100644 qemu/hw/device-assignment.h
>>>       
>> This patch is too big on it's on.  It should be split into logical parts.
>>     
>
> However, it just adds device assignment support and does nothing else. I don't 
> see a way of splitting this any more.
>   

The libkvm changes can go in there own patch.  The changes necessary to 
piix_pci can get in their own patch.  If you get creative, it's probably 
possible to split up device-assignment.c too.

> As you noticed, it's quite different. They have a lot more code in there. (3k+ 
> lines vs 600 lines). I guess most of it went away when we realised we didn't 
> need all that. Also, I noticed most of the code there is not in the qemu 
> style.
>   

What are you looking at?  In my version of xen-unstable, I see 
pass-through.c at 694 lines.  It's all in the right style too.

>> We try to avoid open coding calls to libkvm functions directly within
>> QEMU.  At the least, it should be wrapped with an if (kvm_enabled()).
>>     
>
> With the direct-mmio patch, we just start depending on KVM. Ben-Ami, is there 
> a chance you can keep the MMIO-via-userspace method supported as well for 
> non-kvm hosts?
>   

Open-coding calls to libkvm functions breaks the build when not using 
KVM.  They all need qemu-kvm.c wrappers.

> From your other mail:
>
>   
>> Where did this come from originally?  It's completely different from
>> what is in xen-unstable.  What's in xen-unstable is actually a lot nicer
>> IMHO.
>>     
>
> Nicer in what way?
>
> I think the original code was picked up from before the time it was merged in 
> Xen.
>   

It's in the right style, it avoids layering violations (there are no 
direct calls to the piix device within the code).  At some point in 
time, both KVM and Xen are going to live in the upstream QEMU tree so 
this code will have to be shared.  Since we're basing our code off what 
appears to be older Xen code, I think rebasing it to the latest bits 
makes sense.

Regards,

Anthony Liguori

> Amit
>   

Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Amit Shah]

Hi Anthony,

* On Thursday 28 Aug 2008 18:41:33 Anthony Liguori wrote:
> Amit Shah wrote:

> >> This patch is too big on it's on.  It should be split into logical
> >> parts.
> >
> > However, it just adds device assignment support and does nothing else. I
> > don't see a way of splitting this any more.
>
> The libkvm changes can go in there own patch.  The changes necessary to
> piix_pci can get in their own patch.  If you get creative, it's probably
> possible to split up device-assignment.c too.

Frankly, what purpose would it serve? There's only one call site for the 
functions in libkvm which are only ever going to be used by the device 
assignment code. piix_pci I can agree; they could be shared by others so it 
can be split.

> > As you noticed, it's quite different. They have a lot more code in there.
> > (3k+ lines vs 600 lines). I guess most of it went away when we realised
> > we didn't need all that. Also, I noticed most of the code there is not in
> > the qemu style.
>
> What are you looking at?  In my version of xen-unstable, I see
> pass-through.c at 694 lines.  It's all in the right style too.

I got the xen-unstable hg tree and am looking at tools/ioemu/pass-through.[ch]

> >> We try to avoid open coding calls to libkvm functions directly within
> >> QEMU.  At the least, it should be wrapped with an if (kvm_enabled()).
> >
> > With the direct-mmio patch, we just start depending on KVM. Ben-Ami, is
> > there a chance you can keep the MMIO-via-userspace method supported as
> > well for non-kvm hosts?
>
> Open-coding calls to libkvm functions breaks the build when not using
> KVM.  They all need qemu-kvm.c wrappers.

Of course, that comment's taken. I'm just wondering if Ben-Ami can redo the 
patch so that non-kvm guests can work as well.

> > From your other mail:
> >> Where did this come from originally?  It's completely different from
> >> what is in xen-unstable.  What's in xen-unstable is actually a lot nicer
> >> IMHO.
> >
> > Nicer in what way?
> >
> > I think the original code was picked up from before the time it was
> > merged in Xen.
>
> It's in the right style, it avoids layering violations (there are no
> direct calls to the piix device within the code).  At some point in

Please point me to the code you're looking at.

> time, both KVM and Xen are going to live in the upstream QEMU tree so
> this code will have to be shared.  Since we're basing our code off what
> appears to be older Xen code, I think rebasing it to the latest bits
> makes sense.

Definitely we should work together and have a common codebase. Also, the 
version I have is based on something that was pre-xen; so it's possible all 
the layering work happened later.

Let me see the version you have before I qemu-ify this code.

Thanks,
Amit

Re: [Qemu-devel] Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Ian Jackson]

Amit Shah writes ("[Qemu-devel] Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests"):
> I got the xen-unstable hg tree and am looking at
> tools/ioemu/pass-through.[ch]

That's the old ioemu tree which is pretty much dead now.

> Please point me to the code you're looking at.

You want
 http://xenbits.xensource.com/git-http/qemu-xen-unstable.git

The master branch there is what we're now using.  There are various
other branches includign a few for managing the patch flow to qemu
upstream ...

Ian.

Re: [Qemu-devel] Re: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Amit Shah]

* On Thursday 28 Aug 2008 22:07:50 Ian Jackson wrote:
> Amit Shah writes ("[Qemu-devel] Re: [PATCH 1/1] KVM/userspace: Support for 
assigning PCI devices to guests"):
> > I got the xen-unstable hg tree and am looking at
> > tools/ioemu/pass-through.[ch]
>
> That's the old ioemu tree which is pretty much dead now.

Oh; but the xen.org site only mentions the hg tree.

> > Please point me to the code you're looking at.
>
> You want
>  http://xenbits.xensource.com/git-http/qemu-xen-unstable.git
>
> The master branch there is what we're now using.  There are various
> other branches includign a few for managing the patch flow to qemu
> upstream ...

Thanks.

However, the file here is not too different from what I saw in the hg tree; 
again about 3k+ lines.

Anthony, what're you looking at?

Amit.

RE: [PATCH 1/1] KVM/userspace: Support for assigning PCI devices to guests

[Zhang, Xiantao]

Hi, Amit

> ---
>  libkvm/libkvm-x86.c         |   14 +
>  libkvm/libkvm.h             |   27 ++
>  qemu/Makefile.target        |    1 +
>  qemu/hw/device-assignment.c |  600
>  +++++++++++++++++++++++++++++++++++++++++++
>  qemu/hw/device-assignment.h |   94 +++++++ qemu/hw/isa.h            
>  |    2 + qemu/hw/pc.c                |    9 +
>  qemu/hw/pci.c               |   12 +
>  qemu/hw/pci.h               |    1 +
>  qemu/hw/piix_pci.c          |   19 ++
>  qemu/vl.c                   |   18 ++
>  11 files changed, 797 insertions(+), 0 deletions(-)
>  create mode 100644 qemu/hw/device-assignment.c
>  create mode 100644 qemu/hw/device-assignment.h
> 
> diff --git a/libkvm/libkvm-x86.c b/libkvm/libkvm-x86.c
> index ea97bdd..831823b 100644
> --- a/libkvm/libkvm-x86.c
> +++ b/libkvm/libkvm-x86.c
> @@ -126,6 +126,20 @@ static int kvm_init_tss(kvm_context_t kvm)
>  	return 0;
>  }
> 
> +#ifdef KVM_CAP_DEVICE_ASSIGNMENT
> +int kvm_assign_pci_device(kvm_context_t kvm,
> +			  struct kvm_assigned_pci_dev *assigned_dev)
> +{
> +	return ioctl(kvm->vm_fd, KVM_ASSIGN_PCI_DEVICE, assigned_dev);
> +}
> +
> +int kvm_assign_irq(kvm_context_t kvm,
> +		   struct kvm_assigned_irq *assigned_irq)
> +{
> +	return ioctl(kvm->vm_fd, KVM_ASSIGN_IRQ, assigned_irq);
> +}
> +#endif
> +
>  int kvm_arch_create_default_phys_mem(kvm_context_t kvm,
>  				       unsigned long phys_mem_bytes,
>  				       void **vm_mem)

This stuff had better go into libkvm.c and maybe shared with other
archs, since it is wrapped by KVM_CAP_DEVICE_ASSIGNMENT. 
Xiantao