passthrough: MSI-INTx interrupt translation support
This patch enables Xen to use MSI for MSI-capable devices as the
underlying interrupt source even if the guest does not explicitly
use it. The guest will still see an IO-APIC based INTx interrupt
translated by Xen from the MSI irq.
If the guest enables MSI or MSI-X for the passthrough device, this
translation is automatically turned off. It can also be disabled in
the config file at domain startup time.
Signed-off-by: Qing He <qing.he@xxxxxxxxx>
---
diff --git a/hw/pass-through.c b/hw/pass-through.c
index d280ff6..625e644 100644
--- a/hw/pass-through.c
+++ b/hw/pass-through.c
@@ -34,6 +34,7 @@ struct php_dev {
uint8_t r_bus;
uint8_t r_dev;
uint8_t r_func;
+ char *opt;
};
struct dpci_infos {
@@ -492,7 +493,7 @@ static struct pt_reg_info_tbl pt_emu_reg_msi_tbl[] = {
.size = 2,
.init_val = 0x0000,
.ro_mask = 0x018E,
- .emu_mask = 0xFFFE,
+ .emu_mask = 0xFFFF,
.init = pt_msgctrl_reg_init,
.u.w.read = pt_word_reg_read,
.u.w.write = pt_msgctrl_reg_write,
@@ -692,7 +693,7 @@ static int token_value(char *token)
return strtol(token, NULL, 16);
}
-static int next_bdf(char **str, int *seg, int *bus, int *dev, int *func)
+static int next_bdf(char **str, int *seg, int *bus, int *dev, int *func, char
**opt)
{
char *token;
const char *delim = ":.-";
@@ -711,18 +712,60 @@ static int next_bdf(char **str, int *seg, int *bus, int
*dev, int *func)
*dev = token_value(token);
token = strsep(str, delim);
+ *opt = strchr(token, ',');
+ if (*opt)
+ *(*opt)++ = '\0';
+
*func = token_value(token);
return 1;
}
+static int get_next_keyval(char **option, char **key, char **val)
+{
+ char *opt, *k, *v;
+
+ k = *option;
+ opt = strchr(k, ',');
+ if (opt)
+ *opt++ = '\0';
+ v = strchr(k, '=');
+ if (!v)
+ return -1;
+ *v++ = '\0';
+
+ *key = k;
+ *val = v;
+ *option = opt;
+
+ return 0;
+}
+
+static void msi_set_enable(struct pt_dev *ptdev, int en)
+{
+ uint16_t val;
+ uint32_t address;
+ if (!ptdev->msi)
+ return;
+
+ address = ptdev->msi->ctrl_offset;
+ if (!address)
+ return;
+
+ val = pci_read_word(ptdev->pci_dev, address);
+ val &= ~PCI_MSI_FLAGS_ENABLE;
+ val |= en & PCI_MSI_FLAGS_ENABLE;
+ pci_write_word(ptdev->pci_dev, address, val);
+}
+
/* Insert a new pass-through device into a specific pci slot.
* input dom:bus:dev.func@slot, chose free one if slot == 0
* return -1: required slot not available
* 0: no free hotplug slots, but normal slot should okay
* >0: the new hotplug slot
*/
-static int __insert_to_pci_slot(int bus, int dev, int func, int slot)
+static int __insert_to_pci_slot(int bus, int dev, int func, int slot,
+ char *opt)
{
int i, php_slot;
@@ -759,6 +802,7 @@ found:
dpci_infos.php_devs[php_slot].r_bus = bus;
dpci_infos.php_devs[php_slot].r_dev = dev;
dpci_infos.php_devs[php_slot].r_func = func;
+ dpci_infos.php_devs[php_slot].opt = opt;
return PHP_TO_PCI_SLOT(php_slot);
}
@@ -768,19 +812,19 @@ found:
int insert_to_pci_slot(char *bdf_slt)
{
int seg, bus, dev, func, slot;
- char *bdf_str, *slt_str;
+ char *bdf_str, *slt_str, *opt;
const char *delim="@";
bdf_str = strsep(&bdf_slt, delim);
slt_str = bdf_slt;
slot = token_value(slt_str);
- if ( !next_bdf(&bdf_str, &seg, &bus, &dev, &func))
+ if ( !next_bdf(&bdf_str, &seg, &bus, &dev, &func, &opt))
{
return -1;
}
- return __insert_to_pci_slot(bus, dev, func, slot);
+ return __insert_to_pci_slot(bus, dev, func, slot, opt);
}
@@ -807,8 +851,9 @@ int test_pci_slot(int slot)
int bdf_to_slot(char *bdf_str)
{
int seg, bus, dev, func, i;
+ char *opt;
- if ( !next_bdf(&bdf_str, &seg, &bus, &dev, &func))
+ if ( !next_bdf(&bdf_str, &seg, &bus, &dev, &func, &opt))
{
return -1;
}
@@ -1960,9 +2005,15 @@ static uint32_t pt_msgctrl_reg_init(struct pt_dev *ptdev,
pci_write_word(pdev, real_offset, reg_field & ~PCI_MSI_FLAGS_ENABLE);
}
ptdev->msi->flags |= (reg_field | MSI_FLAG_UNINIT);
+ ptdev->msi->ctrl_offset = real_offset;
/* All register is 0 after reset, except first 4 byte */
reg_field &= reg->ro_mask;
+
+ if (ptdev->msi_trans_cap) {
+ PT_LOG("Turning on MSI-INTx translation\n");
+ ptdev->msi_trans_en = 1;
+ }
return reg_field;
}
@@ -2673,6 +2724,34 @@ static int pt_linkctrl2_reg_write(struct pt_dev *ptdev,
return 0;
}
+static void pt_unmap_msi_translate(struct pt_dev *ptdev)
+{
+ uint16_t e_device, e_intx;
+ int rc;
+
+ /* MSI_ENABLE bit should be disabed until the new handler is set */
+ msi_set_enable(ptdev, 0);
+
+ e_device = (ptdev->dev.devfn >> 3) & 0x1f;
+ /* fix virtual interrupt pin to INTA# */
+ e_intx = 0;
+ rc = xc_domain_unbind_pt_irq(xc_handle, domid, ptdev->msi->pirq,
+ PT_IRQ_TYPE_MSI_TRANSLATE, 0,
+ e_device, e_intx, 0);
+ if (rc < 0)
+ PT_LOG("Error: Unbinding pt irq for MSI-INTx failed! rc=%d\n", rc);
+
+ if (ptdev->machine_irq)
+ {
+ rc = xc_domain_bind_pt_pci_irq(xc_handle, domid, ptdev->machine_irq,
+ 0, e_device, e_intx);
+ if ( rc < 0 )
+ PT_LOG("Error: Rebinding of interrupt failed! rc=%d\n", rc);
+ }
+
+ ptdev->msi_trans_en = 0;
+}
+
/* write Message Control register */
static int pt_msgctrl_reg_write(struct pt_dev *ptdev,
struct pt_reg_tbl *cfg_entry,
@@ -2682,7 +2761,9 @@ static int pt_msgctrl_reg_write(struct pt_dev *ptdev,
uint16_t writable_mask = 0;
uint16_t throughable_mask = 0;
uint16_t old_ctrl = cfg_entry->data;
+ uint8_t e_device, e_intx;
PCIDevice *pd = (PCIDevice *)ptdev;
+ uint16_t val;
/* Currently no support for multi-vector */
if ((*value & PCI_MSI_FLAGS_QSIZE) != 0x0)
@@ -2699,21 +2780,29 @@ static int pt_msgctrl_reg_write(struct pt_dev *ptdev,
PT_LOG("old_ctrl:%04xh new_ctrl:%04xh\n", old_ctrl, cfg_entry->data);
/* create value for writing to I/O device register */
+ val = *value;
throughable_mask = ~reg->emu_mask & valid_mask;
*value = ((*value & throughable_mask) | (dev_value & ~throughable_mask));
/* update MSI */
- if (*value & PCI_MSI_FLAGS_ENABLE)
+ if (val & PCI_MSI_FLAGS_ENABLE)
{
/* setup MSI pirq for the first time */
if (ptdev->msi->flags & MSI_FLAG_UNINIT)
{
- /* Init physical one */
- PT_LOG("setup msi for dev %x\n", pd->devfn);
- if (pt_msi_setup(ptdev))
+ if (ptdev->msi_trans_en) {
+ PT_LOG("guest enabling MSI, disable MSI-INTx translation\n");
+ pt_unmap_msi_translate(ptdev);
+ }
+ else
{
- PT_LOG("pt_msi_setup error!!!\n");
- return -1;
+ /* Init physical one */
+ PT_LOG("setup msi for dev %x\n", pd->devfn);
+ if (pt_msi_setup(ptdev))
+ {
+ PT_LOG("pt_msi_setup error!!!\n");
+ return -1;
+ }
}
pt_msi_update(ptdev);
@@ -2725,6 +2814,12 @@ static int pt_msgctrl_reg_write(struct pt_dev *ptdev,
else
ptdev->msi->flags &= ~PCI_MSI_FLAGS_ENABLE;
+ /* pass through MSI_ENABLE bit when no MSI-INTx translation */
+ if (!ptdev->msi_trans_en) {
+ *value &= ~PCI_MSI_FLAGS_ENABLE;
+ *value |= val & PCI_MSI_FLAGS_ENABLE;
+ }
+
return 0;
}
@@ -2870,7 +2965,13 @@ static int pt_msixctrl_reg_write(struct pt_dev *ptdev,
/* update MSI-X */
if ((*value & PCI_MSIX_ENABLE) && !(*value & PCI_MSIX_MASK))
+ {
+ if (ptdev->msi_trans_en) {
+ PT_LOG("guest enabling MSI-X, disable MSI-INTx translation\n");
+ pt_unmap_msi_translate(ptdev);
+ }
pt_msix_update(ptdev);
+ }
ptdev->msix->enabled = !!(*value & PCI_MSIX_ENABLE);
@@ -2879,7 +2980,8 @@ static int pt_msixctrl_reg_write(struct pt_dev *ptdev,
struct pt_dev * 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, uint32_t machine_irq, struct pci_access *pci_access)
+ uint8_t r_func, uint32_t machine_irq, struct pci_access *pci_access,
+ char *opt)
{
int rc = -1, i;
struct pt_dev *assigned_device = NULL;
@@ -2887,6 +2989,8 @@ struct pt_dev * register_real_device(PCIBus *e_bus,
uint8_t e_device, e_intx;
struct pci_config_cf8 machine_bdf;
int free_pci_slot = -1;
+ char *key, *val;
+ int msi_translate;
PT_LOG("Assigning real physical device %02x:%02x.%x ...\n",
r_bus, r_dev, r_func);
@@ -2908,13 +3012,41 @@ struct pt_dev * register_real_device(PCIBus *e_bus,
if ( e_devfn == PT_VIRT_DEVFN_AUTO ) {
/*indicate a static assignment(not hotplug), so find a free PCI hot
plug slot */
- free_pci_slot = __insert_to_pci_slot(r_bus, r_dev, r_func, 0);
+ free_pci_slot = __insert_to_pci_slot(r_bus, r_dev, r_func, 0, NULL);
if ( free_pci_slot > 0 )
e_devfn = free_pci_slot << 3;
else
PT_LOG("Error: no free virtual PCI hot plug slot, thus no live
migration.\n");
}
+ msi_translate = direct_pci_msitranslate;
+ while (opt) {
+ if (get_next_keyval(&opt, &key, &val)) {
+ PT_LOG("Error: unrecognized PCI assignment option \"%s\"\n", opt);
+ break;
+ }
+
+ if (strcmp(key, "msitranslate") == 0)
+ {
+ if (strcmp(val, "0") == 0 || strcmp(val, "no") == 0)
+ {
+ PT_LOG("Disable MSI translation via per device option\n");
+ msi_translate = 0;
+ }
+ else if (strcmp(val, "1") == 0 || strcmp(val, "yes") == 0)
+ {
+ PT_LOG("Enable MSI translation via per device option\n");
+ msi_translate = 1;
+ }
+ else
+ PT_LOG("Error: unrecognized value for msitranslate=\n");
+ }
+ else
+ PT_LOG("Error: unrecognized PCI assignment option \"%s=%s\"\n",
key, val);
+
+ }
+
+
/* Register device */
assigned_device = (struct pt_dev *) pci_register_device(e_bus, e_dev_name,
sizeof(struct pt_dev), e_devfn,
@@ -2929,6 +3061,7 @@ struct pt_dev * register_real_device(PCIBus *e_bus,
dpci_infos.php_devs[PCI_TO_PHP_SLOT(free_pci_slot)].pt_dev =
assigned_device;
assigned_device->pci_dev = pci_dev;
+ assigned_device->msi_trans_cap = msi_translate;
/* Assign device */
machine_bdf.reg = 0;
@@ -2960,6 +3093,28 @@ struct pt_dev * register_real_device(PCIBus *e_bus,
/* fix virtual interrupt pin to INTA# */
e_intx = 0;
+ while (assigned_device->msi_trans_en)
+ {
+ if (pt_msi_setup(assigned_device))
+ {
+ PT_LOG("Error: MSI-INTx translation MSI setup failed, fallback\n");
+ assigned_device->msi_trans_en = 0;
+ break;
+ }
+
+ rc = xc_domain_bind_pt_irq(xc_handle, domid,
assigned_device->msi->pirq,
+ PT_IRQ_TYPE_MSI_TRANSLATE, 0,
+ e_device, e_intx, 0);
+ if ( rc < 0)
+ {
+ PT_LOG("Error: MSI-INTx translation bind failed, fallback\n");
+ assigned_device->msi_trans_en = 0;
+ break;
+ }
+ msi_set_enable(assigned_device, 1);
+ break;
+ }
+
if ( PT_MACHINE_IRQ_AUTO == machine_irq )
{
int pirq = pci_dev->irq;
@@ -2973,9 +3125,15 @@ struct pt_dev * register_real_device(PCIBus *e_bus,
PT_LOG("Error: Mapping irq failed, rc = %d\n", rc);
}
else
+ {
machine_irq = pirq;
+ assigned_device->machine_irq = pirq;
+ }
}
+ if (assigned_device->msi_trans_en)
+ goto out;
+
/* bind machine_irq to device */
if ( 0 != machine_irq )
{
@@ -2995,8 +3153,9 @@ struct pt_dev * register_real_device(PCIBus *e_bus,
}
out:
- PT_LOG("Real physical device %02x:%02x.%x registered successfuly!\n",
- r_bus, r_dev, r_func);
+ PT_LOG("Real physical device %02x:%02x.%x registered successfuly!\n"
+ "IRQ type = %s\n", r_bus, r_dev, r_func,
+ assigned_device->msi_trans_en? "MSI-INTx":"INTx");
return assigned_device;
}
@@ -3029,9 +3188,9 @@ int unregister_real_device(int php_slot)
e_device = (assigned_device->dev.devfn >> 3) & 0x1f;
/* fix virtual interrupt pin to INTA# */
e_intx = 0;
- machine_irq = pci_dev->irq;
+ machine_irq = assigned_device->machine_irq;
- if ( machine_irq != 0 ) {
+ if ( assigned_device->msi_trans_en == 0 && machine_irq ) {
rc = xc_domain_unbind_pt_irq(xc_handle, domid, machine_irq,
PT_IRQ_TYPE_PCI, 0,
e_device, e_intx, 0);
if ( rc < 0 )
@@ -3040,6 +3199,16 @@ int unregister_real_device(int php_slot)
PT_LOG("Error: Unbinding of interrupt failed! rc=%d\n", rc);
}
}
+ else if (assigned_device->msi_trans_en)
+ {
+ rc = xc_domain_unbind_pt_irq(xc_handle, domid,
assigned_device->msi->pirq,
+ PT_IRQ_TYPE_MSI_TRANSLATE, 0,
+ e_device, e_intx, 0);
+ if (rc < 0)
+ PT_LOG("Error: Unbinding pt irq for MSI-INTx failed! rc=%d\n", rc);
+ }
+
+ /* TODO: unmap passthrough MSI and MSI-X irqs */
/* delete all emulated config registers */
pt_config_delete(assigned_device);
@@ -3075,7 +3244,10 @@ int power_on_php_slot(int php_slot)
php_dev->r_dev,
php_dev->r_func,
PT_MACHINE_IRQ_AUTO,
- dpci_infos.pci_access);
+ dpci_infos.pci_access,
+ php_dev->opt);
+
+ php_dev->opt = NULL;
php_dev->pt_dev = pt_dev;
@@ -3097,6 +3269,7 @@ int pt_init(PCIBus *e_bus, const char *direct_pci)
char slot_str[8];
char *direct_pci_head = NULL;
char *direct_pci_p = NULL;
+ char *opt;
/* Initialize libpci */
pci_access = pci_alloc();
@@ -3125,11 +3298,11 @@ int pt_init(PCIBus *e_bus, const char *direct_pci)
vslots = qemu_mallocz ( strlen(direct_pci) / 3 );
/* Assign given devices to guest */
- while ( next_bdf(&direct_pci_p, &seg, &b, &d, &f) )
+ while ( next_bdf(&direct_pci_p, &seg, &b, &d, &f, &opt) )
{
/* Register real device with the emulated bus */
pt_dev = register_real_device(e_bus, "DIRECT PCI", PT_VIRT_DEVFN_AUTO,
- b, d, f, PT_MACHINE_IRQ_AUTO, pci_access);
+ b, d, f, PT_MACHINE_IRQ_AUTO, pci_access, opt);
if ( pt_dev == NULL )
{
PT_LOG("Error: Registration failed (%02x:%02x.%x)\n", b, d, f);
diff --git a/hw/pass-through.h b/hw/pass-through.h
index 8aa664b..a7d2727 100644
--- a/hw/pass-through.h
+++ b/hw/pass-through.h
@@ -121,6 +121,7 @@ struct pt_region {
struct pt_msi_info {
uint32_t flags;
+ uint32_t ctrl_offset; /* saved control offset */
int pirq; /* guest pirq corresponding */
uint32_t addr_lo; /* guest message address */
uint32_t addr_hi; /* guest message upper address */
@@ -158,6 +159,10 @@ struct pt_dev {
/* emul reg group list */
struct pt_msi_info *msi; /* MSI virtualization */
struct pt_msix_info *msix; /* MSI-X virtualization */
+ int machine_irq; /* saved pirq */
+ /* Physical MSI to guest INTx translation when possible */
+ int msi_trans_cap;
+ int msi_trans_en;
};
/* Used for formatting PCI BDF into cf8 format */
diff --git a/hw/pci.h b/hw/pci.h
index 4adc4d7..a527a39 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -64,6 +64,7 @@ struct PCIDevice {
};
extern char direct_pci_str[];
+extern int direct_pci_msitranslate;
PCIDevice *pci_register_device(PCIBus *bus, const char *name,
int instance_size, int devfn,
diff --git a/xenstore.c b/xenstore.c
index 86e8b63..ff3d023 100644
--- a/xenstore.c
+++ b/xenstore.c
@@ -290,8 +290,10 @@ const char *xenstore_get_guest_uuid(void) {
#endif
}
-#define DIRECT_PCI_STR_LEN 160
+#define DIRECT_PCI_STR_LEN 512
+#define PT_PCI_MSITRANSLATE_DEFAULT 1
char direct_pci_str[DIRECT_PCI_STR_LEN];
+int direct_pci_msitranslate;
void xenstore_parse_domain_config(int hvm_domid)
{
char **e_danger = NULL;
@@ -556,20 +558,50 @@ void xenstore_parse_domain_config(int hvm_domid)
free(dev);
dev = xs_read(xsh, XBT_NULL, buf, &len);
- if ( strlen(dev) + strlen(direct_pci_str) > DIRECT_PCI_STR_LEN ) {
+ if ( strlen(dev) + strlen(direct_pci_str) > DIRECT_PCI_STR_LEN -
1) {
fprintf(stderr, "qemu: too many pci pass-through devices\n");
memset(direct_pci_str, 0, DIRECT_PCI_STR_LEN);
goto out;
}
+
/* append to direct_pci_str */
+ if ( !dev )
+ continue;
+
+ strcat(direct_pci_str, dev);
+
+ if (pasprintf(&buf, "/local/domain/0/backend/pci/%u/%u/opts-%d",
+ hvm_domid, pci_devid, i) != -1) {
+ free(dev);
+ dev = xs_read(xsh, XBT_NULL, buf, &len);
+ }
if ( dev ) {
+ if ( strlen(dev) + strlen(direct_pci_str) > DIRECT_PCI_STR_LEN
- 2) {
+ fprintf(stderr, "qemu: too many pci pass-through
devices\n");
+ memset(direct_pci_str, 0, DIRECT_PCI_STR_LEN);
+ goto out;
+ }
+ strcat(direct_pci_str, ",");
strcat(direct_pci_str, dev);
- strcat(direct_pci_str, "-");
}
+
+ strcat(direct_pci_str, "-");
}
}
+ /* get the pci pass-through parameter */
+ if (pasprintf(&buf, "/local/domain/0/backend/pci/%u/%u/msitranslate",
+ hvm_domid, pci_devid) == -1)
+ goto out;
+
+ free(params);
+ params = xs_read(xsh, XBT_NULL, buf, &len);
+ if (params)
+ direct_pci_msitranslate = atoi(params);
+ else
+ direct_pci_msitranslate = PT_PCI_MSITRANSLATE_DEFAULT;
+
out:
free(danger_type);
free(params);
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