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-rw-r--r--tools/lguest/lguest.c216
1 files changed, 211 insertions, 5 deletions
diff --git a/tools/lguest/lguest.c b/tools/lguest/lguest.c
index e52a357..0f29657 100644
--- a/tools/lguest/lguest.c
+++ b/tools/lguest/lguest.c
@@ -42,6 +42,7 @@
#include <pwd.h>
#include <grp.h>
#include <sys/user.h>
+#include <linux/pci_regs.h>
#ifndef VIRTIO_F_ANY_LAYOUT
#define VIRTIO_F_ANY_LAYOUT 27
@@ -125,6 +126,21 @@ struct device_list {
/* The list of Guest devices, based on command line arguments. */
static struct device_list devices;
+/* This is the layout (little-endian) of the PCI config space. */
+struct pci_config {
+ u16 vendor_id, device_id;
+ u16 command, status;
+ u8 revid, prog_if, subclass, class;
+ u8 cacheline_size, lat_timer, header_type, bist;
+ u32 bar[6];
+ u32 cardbus_cis_ptr;
+ u16 subsystem_vendor_id, subsystem_device_id;
+ u32 expansion_rom_addr;
+ u8 capabilities, reserved1[3];
+ u32 reserved2;
+ u8 irq_line, irq_pin, min_grant, max_latency;
+};
+
/* The device structure describes a single device. */
struct device {
/* The linked-list pointer. */
@@ -146,6 +162,15 @@ struct device {
/* Is it operational */
bool running;
+ /* PCI configuration */
+ union {
+ struct pci_config config;
+ u32 config_words[sizeof(struct pci_config) / sizeof(u32)];
+ };
+
+ /* Device-specific config hangs off the end of this. */
+ struct virtio_pci_mmio *mmio;
+
/* PCI MMIO resources (all in BAR0) */
size_t mmio_size;
u32 mmio_addr;
@@ -1173,6 +1198,169 @@ static void handle_output(unsigned long addr)
strnlen(from_guest_phys(addr), guest_limit - addr));
}
+/*L:217
+ * We do PCI. This is mainly done to let us test the kernel virtio PCI
+ * code.
+ */
+
+/* The IO ports used to read the PCI config space. */
+#define PCI_CONFIG_ADDR 0xCF8
+#define PCI_CONFIG_DATA 0xCFC
+
+/*
+ * Not really portable, but does help readability: this is what the Guest
+ * writes to the PCI_CONFIG_ADDR IO port.
+ */
+union pci_config_addr {
+ struct {
+ unsigned mbz: 2;
+ unsigned offset: 6;
+ unsigned funcnum: 3;
+ unsigned devnum: 5;
+ unsigned busnum: 8;
+ unsigned reserved: 7;
+ unsigned enabled : 1;
+ } bits;
+ u32 val;
+};
+
+/*
+ * We cache what they wrote to the address port, so we know what they're
+ * talking about when they access the data port.
+ */
+static union pci_config_addr pci_config_addr;
+
+static struct device *find_pci_device(unsigned int index)
+{
+ return devices.pci[index];
+}
+
+/* PCI can do 1, 2 and 4 byte reads; we handle that here. */
+static void ioread(u16 off, u32 v, u32 mask, u32 *val)
+{
+ assert(off < 4);
+ assert(mask == 0xFF || mask == 0xFFFF || mask == 0xFFFFFFFF);
+ *val = (v >> (off * 8)) & mask;
+}
+
+/* PCI can do 1, 2 and 4 byte writes; we handle that here. */
+static void iowrite(u16 off, u32 v, u32 mask, u32 *dst)
+{
+ assert(off < 4);
+ assert(mask == 0xFF || mask == 0xFFFF || mask == 0xFFFFFFFF);
+ *dst &= ~(mask << (off * 8));
+ *dst |= (v & mask) << (off * 8);
+}
+
+/*
+ * Where PCI_CONFIG_DATA accesses depends on the previous write to
+ * PCI_CONFIG_ADDR.
+ */
+static struct device *dev_and_reg(u32 *reg)
+{
+ if (!pci_config_addr.bits.enabled)
+ return NULL;
+
+ if (pci_config_addr.bits.funcnum != 0)
+ return NULL;
+
+ if (pci_config_addr.bits.busnum != 0)
+ return NULL;
+
+ if (pci_config_addr.bits.offset * 4 >= sizeof(struct pci_config))
+ return NULL;
+
+ *reg = pci_config_addr.bits.offset;
+ return find_pci_device(pci_config_addr.bits.devnum);
+}
+
+/* Is this accessing the PCI config address port?. */
+static bool is_pci_addr_port(u16 port)
+{
+ return port >= PCI_CONFIG_ADDR && port < PCI_CONFIG_ADDR + 4;
+}
+
+static bool pci_addr_iowrite(u16 port, u32 mask, u32 val)
+{
+ iowrite(port - PCI_CONFIG_ADDR, val, mask,
+ &pci_config_addr.val);
+ verbose("PCI%s: %#x/%x: bus %u dev %u func %u reg %u\n",
+ pci_config_addr.bits.enabled ? "" : " DISABLED",
+ val, mask,
+ pci_config_addr.bits.busnum,
+ pci_config_addr.bits.devnum,
+ pci_config_addr.bits.funcnum,
+ pci_config_addr.bits.offset);
+ return true;
+}
+
+static void pci_addr_ioread(u16 port, u32 mask, u32 *val)
+{
+ ioread(port - PCI_CONFIG_ADDR, pci_config_addr.val, mask, val);
+}
+
+/* Is this accessing the PCI config data port?. */
+static bool is_pci_data_port(u16 port)
+{
+ return port >= PCI_CONFIG_DATA && port < PCI_CONFIG_DATA + 4;
+}
+
+static bool pci_data_iowrite(u16 port, u32 mask, u32 val)
+{
+ u32 reg, portoff;
+ struct device *d = dev_and_reg(&reg);
+
+ /* Complain if they don't belong to a device. */
+ if (!d)
+ return false;
+
+ /* They can do 1 byte writes, etc. */
+ portoff = port - PCI_CONFIG_DATA;
+
+ /*
+ * PCI uses a weird way to determine the BAR size: the OS
+ * writes all 1's, and sees which ones stick.
+ */
+ if (&d->config_words[reg] == &d->config.bar[0]) {
+ int i;
+
+ iowrite(portoff, val, mask, &d->config.bar[0]);
+ for (i = 0; (1 << i) < d->mmio_size; i++)
+ d->config.bar[0] &= ~(1 << i);
+ return true;
+ } else if ((&d->config_words[reg] > &d->config.bar[0]
+ && &d->config_words[reg] <= &d->config.bar[6])
+ || &d->config_words[reg] == &d->config.expansion_rom_addr) {
+ /* Allow writing to any other BAR, or expansion ROM */
+ iowrite(portoff, val, mask, &d->config_words[reg]);
+ return true;
+ /* We let them overide latency timer and cacheline size */
+ } else if (&d->config_words[reg] == (void *)&d->config.cacheline_size) {
+ /* Only let them change the first two fields. */
+ if (mask == 0xFFFFFFFF)
+ mask = 0xFFFF;
+ iowrite(portoff, val, mask, &d->config_words[reg]);
+ return true;
+ } else if (&d->config_words[reg] == (void *)&d->config.command
+ && mask == 0xFFFF) {
+ /* Ignore command writes. */
+ return true;
+ }
+
+ /* Complain about other writes. */
+ return false;
+}
+
+static void pci_data_ioread(u16 port, u32 mask, u32 *val)
+{
+ u32 reg;
+ struct device *d = dev_and_reg(&reg);
+
+ if (!d)
+ return;
+ ioread(port - PCI_CONFIG_DATA, d->config_words[reg], mask, val);
+}
+
/*L:216
* This is where we emulate a handful of Guest instructions. It's ugly
* and we used to do it in the kernel but it grew over time.
@@ -1284,7 +1472,7 @@ static void emulate_insn(const u8 insn[])
unsigned int insnlen = 0, in = 0, small_operand = 0, byte_access;
unsigned int eax, port, mask;
/*
- * We always return all-ones on IO port reads, which traditionally
+ * Default is to return all-ones on IO port reads, which traditionally
* means "there's nothing there".
*/
u32 val = 0xFFFFFFFF;
@@ -1359,10 +1547,6 @@ static void emulate_insn(const u8 insn[])
else
mask = 0xFFFFFFFF;
- /* This is the PS/2 keyboard status; 1 means ready for output */
- if (port == 0x64)
- val = 1;
-
/*
* If it was an "IN" instruction, they expect the result to be read
* into %eax, so we change %eax.
@@ -1370,12 +1554,30 @@ static void emulate_insn(const u8 insn[])
eax = getreg(eax);
if (in) {
+ /* This is the PS/2 keyboard status; 1 means ready for output */
+ if (port == 0x64)
+ val = 1;
+ else if (is_pci_addr_port(port))
+ pci_addr_ioread(port, mask, &val);
+ else if (is_pci_data_port(port))
+ pci_data_ioread(port, mask, &val);
+
/* Clear the bits we're about to read */
eax &= ~mask;
/* Copy bits in from val. */
eax |= val & mask;
/* Now update the register. */
setreg(eax, eax);
+ } else {
+ if (is_pci_addr_port(port)) {
+ if (!pci_addr_iowrite(port, mask, eax))
+ goto bad_io;
+ } else if (is_pci_data_port(port)) {
+ if (!pci_data_iowrite(port, mask, eax))
+ goto bad_io;
+ }
+ /* There are many other ports, eg. CMOS clock, serial
+ * and parallel ports, so we ignore them all. */
}
verbose("IO %s of %x to %u: %#08x\n",
@@ -1385,6 +1587,10 @@ skip_insn:
setreg(eip, getreg(eip) + insnlen);
return;
+bad_io:
+ warnx("Attempt to %s port %u (%#x mask)",
+ in ? "read from" : "write to", port, mask);
+
no_emulate:
/* Inject trap into Guest. */
if (write(lguest_fd, args, sizeof(args)) < 0)

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