From e5fc7345412d5e4758fcef55a74354c5cbefd61e Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Wed, 1 Dec 2010 14:51:44 +0000 Subject: xen: use PHYSDEVOP_get_free_pirq to implement find_unbound_pirq Use the new hypercall PHYSDEVOP_get_free_pirq to ask Xen to allocate a pirq. Remove the unsupported PHYSDEVOP_get_nr_pirqs hypercall to get the amount of pirq available. This fixes find_unbound_pirq that otherwise would return a number starting from nr_irqs that might very well be out of range in Xen. The symptom of this bug is that when you passthrough an MSI capable pci device to a PV on HVM guest, Linux would fail to enable MSIs on the device. Signed-off-by: Stefano Stabellini --- drivers/xen/events.c | 45 ++++++++++++++++++++------------------------- 1 file changed, 20 insertions(+), 25 deletions(-) (limited to 'drivers/xen') diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 2811bb988ea0..7ab43c33f746 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -105,7 +105,6 @@ struct irq_info static struct irq_info *irq_info; static int *pirq_to_irq; -static int nr_pirqs; static int *evtchn_to_irq; struct cpu_evtchn_s { @@ -385,12 +384,17 @@ static int get_nr_hw_irqs(void) return ret; } -/* callers of this function should make sure that PHYSDEVOP_get_nr_pirqs - * succeeded otherwise nr_pirqs won't hold the right value */ -static int find_unbound_pirq(void) +static int find_unbound_pirq(int type) { - int i; - for (i = nr_pirqs-1; i >= 0; i--) { + int rc, i; + struct physdev_get_free_pirq op_get_free_pirq; + op_get_free_pirq.type = type; + + rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq); + if (!rc) + return op_get_free_pirq.pirq; + + for (i = 0; i < nr_irqs; i++) { if (pirq_to_irq[i] < 0) return i; } @@ -611,10 +615,10 @@ int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name) spin_lock(&irq_mapping_update_lock); - if ((pirq > nr_pirqs) || (gsi > nr_irqs)) { + if ((pirq > nr_irqs) || (gsi > nr_irqs)) { printk(KERN_WARNING "xen_map_pirq_gsi: %s %s is incorrect!\n", - pirq > nr_pirqs ? "nr_pirqs" :"", - gsi > nr_irqs ? "nr_irqs" : ""); + pirq > nr_irqs ? "pirq" :"", + gsi > nr_irqs ? "gsi" : ""); goto out; } @@ -672,7 +676,7 @@ void xen_allocate_pirq_msi(char *name, int *irq, int *pirq) if (*irq == -1) goto out; - *pirq = find_unbound_pirq(); + *pirq = find_unbound_pirq(MAP_PIRQ_TYPE_MSI); if (*pirq == -1) goto out; @@ -1506,26 +1510,17 @@ void xen_callback_vector(void) {} void __init xen_init_IRQ(void) { - int i, rc; - struct physdev_nr_pirqs op_nr_pirqs; + int i; cpu_evtchn_mask_p = kcalloc(nr_cpu_ids, sizeof(struct cpu_evtchn_s), GFP_KERNEL); irq_info = kcalloc(nr_irqs, sizeof(*irq_info), GFP_KERNEL); - rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_nr_pirqs, &op_nr_pirqs); - if (rc < 0) { - nr_pirqs = nr_irqs; - if (rc != -ENOSYS) - printk(KERN_WARNING "PHYSDEVOP_get_nr_pirqs returned rc=%d\n", rc); - } else { - if (xen_pv_domain() && !xen_initial_domain()) - nr_pirqs = max((int)op_nr_pirqs.nr_pirqs, nr_irqs); - else - nr_pirqs = op_nr_pirqs.nr_pirqs; - } - pirq_to_irq = kcalloc(nr_pirqs, sizeof(*pirq_to_irq), GFP_KERNEL); - for (i = 0; i < nr_pirqs; i++) + /* We are using nr_irqs as the maximum number of pirq available but + * that number is actually chosen by Xen and we don't know exactly + * what it is. Be careful choosing high pirq numbers. */ + pirq_to_irq = kcalloc(nr_irqs, sizeof(*pirq_to_irq), GFP_KERNEL); + for (i = 0; i < nr_irqs; i++) pirq_to_irq[i] = -1; evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq), -- cgit v1.2.3 From af42b8d12f8adec6711cb824549a0edac6a4ae8f Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Wed, 1 Dec 2010 14:51:44 +0000 Subject: xen: fix MSI setup and teardown for PV on HVM guests When remapping MSIs into pirqs for PV on HVM guests, qemu is responsible for doing the actual mapping and unmapping. We only give qemu the desired pirq number when we ask to do the mapping the first time, after that we should be reading back the pirq number from qemu every time we want to re-enable the MSI. This fixes a bug in xen_hvm_setup_msi_irqs that manifests itself when trying to enable the same MSI for the second time: the old MSI to pirq mapping is still valid at this point but xen_hvm_setup_msi_irqs would try to assign a new pirq anyway. A simple way to reproduce this bug is to assign an MSI capable network card to a PV on HVM guest, if the user brings down the corresponding ethernet interface and up again, Linux would fail to enable MSIs on the device. Signed-off-by: Stefano Stabellini --- drivers/xen/events.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) (limited to 'drivers/xen') diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 7ab43c33f746..f78945ce8aeb 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -668,17 +668,21 @@ out: #include #include "../pci/msi.h" -void xen_allocate_pirq_msi(char *name, int *irq, int *pirq) +void xen_allocate_pirq_msi(char *name, int *irq, int *pirq, int alloc) { spin_lock(&irq_mapping_update_lock); - *irq = find_unbound_irq(); - if (*irq == -1) - goto out; + if (alloc & XEN_ALLOC_IRQ) { + *irq = find_unbound_irq(); + if (*irq == -1) + goto out; + } - *pirq = find_unbound_pirq(MAP_PIRQ_TYPE_MSI); - if (*pirq == -1) - goto out; + if (alloc & XEN_ALLOC_PIRQ) { + *pirq = find_unbound_pirq(MAP_PIRQ_TYPE_MSI); + if (*pirq == -1) + goto out; + } set_irq_chip_and_handler_name(*irq, &xen_pirq_chip, handle_level_irq, name); @@ -766,6 +770,7 @@ int xen_destroy_irq(int irq) printk(KERN_WARNING "unmap irq failed %d\n", rc); goto out; } + pirq_to_irq[info->u.pirq.pirq] = -1; } irq_info[irq] = mk_unbound_info(); @@ -786,6 +791,11 @@ int xen_gsi_from_irq(unsigned irq) return gsi_from_irq(irq); } +int xen_irq_from_pirq(unsigned pirq) +{ + return pirq_to_irq[pirq]; +} + int bind_evtchn_to_irq(unsigned int evtchn) { int irq; -- cgit v1.2.3 From 6411fe69b8c4fd7811339c88c1843d562099fa2b Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Wed, 1 Dec 2010 14:51:44 +0000 Subject: xen: resume the pv console for hvm guests too Signed-off-by: Stefano Stabellini --- drivers/xen/manage.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/xen') diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index ef9c7db52077..db8c4c4ac880 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -49,6 +49,7 @@ static int xen_hvm_suspend(void *data) if (!*cancelled) { xen_irq_resume(); + xen_console_resume(); xen_timer_resume(); } -- cgit v1.2.3 From 9a069c33c53c2e72ec1b76106be73df044af0195 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Wed, 1 Dec 2010 14:51:44 +0000 Subject: xen: fix save/restore for PV on HVM guests with pirq remapping Re-map and re-bind all the pirqs at resume time. Signed-off-by: Stefano Stabellini --- drivers/xen/events.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'drivers/xen') diff --git a/drivers/xen/events.c b/drivers/xen/events.c index f78945ce8aeb..f34288a5400c 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -1293,6 +1293,42 @@ static int retrigger_dynirq(unsigned int irq) return ret; } +static void restore_cpu_pirqs(void) +{ + int pirq, rc, irq, gsi; + struct physdev_map_pirq map_irq; + + for (pirq = 0; pirq < nr_irqs; pirq++) { + irq = pirq_to_irq[pirq]; + if (irq == -1) + continue; + + /* save/restore of PT devices doesn't work, so at this point the + * only devices present are GSI based emulated devices */ + gsi = gsi_from_irq(irq); + if (!gsi) + continue; + + map_irq.domid = DOMID_SELF; + map_irq.type = MAP_PIRQ_TYPE_GSI; + map_irq.index = gsi; + map_irq.pirq = pirq; + + rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq); + if (rc) { + printk(KERN_WARNING "xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n", + gsi, irq, pirq, rc); + irq_info[irq] = mk_unbound_info(); + pirq_to_irq[pirq] = -1; + continue; + } + + printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq); + + startup_pirq(irq); + } +} + static void restore_cpu_virqs(unsigned int cpu) { struct evtchn_bind_virq bind_virq; @@ -1436,6 +1472,8 @@ void xen_irq_resume(void) unmask_evtchn(evtchn); } + + restore_cpu_pirqs(); } static struct irq_chip xen_dynamic_chip __read_mostly = { -- cgit v1.2.3