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 --- include/xen/interface/physdev.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include') diff --git a/include/xen/interface/physdev.h b/include/xen/interface/physdev.h index 2b2c66c3df00..534cac89a77d 100644 --- a/include/xen/interface/physdev.h +++ b/include/xen/interface/physdev.h @@ -188,6 +188,16 @@ struct physdev_nr_pirqs { uint32_t nr_pirqs; }; +/* type is MAP_PIRQ_TYPE_GSI or MAP_PIRQ_TYPE_MSI + * the hypercall returns a free pirq */ +#define PHYSDEVOP_get_free_pirq 23 +struct physdev_get_free_pirq { + /* IN */ + int type; + /* OUT */ + uint32_t pirq; +}; + /* * Notify that some PIRQ-bound event channels have been unmasked. * ** This command is obsolete since interface version 0x00030202 and is ** -- cgit v1.2.3 From af42b8d12f8adec6711cb824549a0edac6a4ae8f Mon Sep 17 00:00:00 2001 From: Stefano Stabellini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 --- include/xen/events.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/xen/events.h b/include/xen/events.h index 646dd17d3aa4..00f53ddcc062 100644 --- a/include/xen/events.h +++ b/include/xen/events.h @@ -76,7 +76,9 @@ int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name); #ifdef CONFIG_PCI_MSI /* Allocate an irq and a pirq to be used with MSIs. */ -void xen_allocate_pirq_msi(char *name, int *irq, int *pirq); +#define XEN_ALLOC_PIRQ (1 << 0) +#define XEN_ALLOC_IRQ (1 << 1) +void xen_allocate_pirq_msi(char *name, int *irq, int *pirq, int alloc_mask); int xen_create_msi_irq(struct pci_dev *dev, struct msi_desc *msidesc, int type); #endif @@ -89,4 +91,7 @@ int xen_vector_from_irq(unsigned pirq); /* Return gsi allocated to pirq */ int xen_gsi_from_irq(unsigned pirq); +/* Return irq from pirq */ +int xen_irq_from_pirq(unsigned pirq); + #endif /* _XEN_EVENTS_H */ -- cgit v1.2.3