From bce21a2b48ede7cbcab92db18bc956daf1d5c246 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Wed, 10 Mar 2021 11:45:26 +0100 Subject: [PATCH] Xen/gnttab: introduce common INVALID_GRANT_{HANDLE,REF} It's not helpful if every driver has to cook its own. Generalize xenbus'es INVALID_GRANT_HANDLE and pcifront's INVALID_GRANT_REF (which shouldn't have expanded to zero to begin with). Use the constants in p2m.c and gntdev.c right away, and update field types where necessary so they would match with the constants' types (albeit without touching struct ioctl_gntdev_grant_ref's ref field, as that's part of the public interface of the kernel and would require introducing a dependency on Xen's grant_table.h public header). Signed-off-by: Jan Beulich Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/db7c38a5-0d75-d5d1-19de-e5fe9f0b9c48@suse.com Signed-off-by: Boris Ostrovsky --- arch/arm/xen/p2m.c | 3 ++- arch/x86/xen/p2m.c | 4 ++-- drivers/pci/xen-pcifront.c | 4 ++-- drivers/xen/gntdev.c | 24 +++++++++++++----------- include/xen/grant_table.h | 7 +++++++ include/xen/xenbus.h | 1 - 6 files changed, 26 insertions(+), 17 deletions(-) diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c index 5316cf36cb57e..84a1cea1f43b9 100644 --- a/arch/arm/xen/p2m.c +++ b/arch/arm/xen/p2m.c @@ -11,6 +11,7 @@ #include #include +#include #include #include @@ -109,7 +110,7 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, map_ops[i].status = GNTST_general_error; unmap.host_addr = map_ops[i].host_addr, unmap.handle = map_ops[i].handle; - map_ops[i].handle = ~0; + map_ops[i].handle = INVALID_GRANT_HANDLE; if (map_ops[i].flags & GNTMAP_device_map) unmap.dev_bus_addr = map_ops[i].dev_bus_addr; else diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index e912992e0b77f..17d80f751fcb2 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -741,7 +741,7 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, map_ops[i].status = GNTST_general_error; unmap[0].host_addr = map_ops[i].host_addr, unmap[0].handle = map_ops[i].handle; - map_ops[i].handle = ~0; + map_ops[i].handle = INVALID_GRANT_HANDLE; if (map_ops[i].flags & GNTMAP_device_map) unmap[0].dev_bus_addr = map_ops[i].dev_bus_addr; else @@ -751,7 +751,7 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, kmap_ops[i].status = GNTST_general_error; unmap[1].host_addr = kmap_ops[i].host_addr, unmap[1].handle = kmap_ops[i].handle; - kmap_ops[i].handle = ~0; + kmap_ops[i].handle = INVALID_GRANT_HANDLE; if (kmap_ops[i].flags & GNTMAP_device_map) unmap[1].dev_bus_addr = kmap_ops[i].dev_bus_addr; else diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c index c6fe0cfec0f68..2d75026482197 100644 --- a/drivers/pci/xen-pcifront.c +++ b/drivers/pci/xen-pcifront.c @@ -26,7 +26,7 @@ #include #include -#define INVALID_GRANT_REF (0) + #define INVALID_EVTCHN (-1) struct pci_bus_entry { @@ -42,7 +42,7 @@ struct pcifront_device { struct list_head root_buses; int evtchn; - int gnt_ref; + grant_ref_t gnt_ref; int irq; diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index b60ebd8bdb261..ebfd3e7b20d47 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -186,11 +186,11 @@ struct gntdev_grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count, goto err; for (i = 0; i < count; i++) { - add->map_ops[i].handle = -1; - add->unmap_ops[i].handle = -1; + add->map_ops[i].handle = INVALID_GRANT_HANDLE; + add->unmap_ops[i].handle = INVALID_GRANT_HANDLE; if (use_ptemod) { - add->kmap_ops[i].handle = -1; - add->kunmap_ops[i].handle = -1; + add->kmap_ops[i].handle = INVALID_GRANT_HANDLE; + add->kunmap_ops[i].handle = INVALID_GRANT_HANDLE; } } @@ -279,7 +279,7 @@ static int find_grant_ptes(pte_t *pte, unsigned long addr, void *data) map->grants[pgnr].ref, map->grants[pgnr].domid); gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags, - -1 /* handle */); + INVALID_GRANT_HANDLE); return 0; } @@ -297,7 +297,7 @@ int gntdev_map_grant_pages(struct gntdev_grant_map *map) if (!use_ptemod) { /* Note: it could already be mapped */ - if (map->map_ops[0].handle != -1) + if (map->map_ops[0].handle != INVALID_GRANT_HANDLE) return 0; for (i = 0; i < map->count; i++) { unsigned long addr = (unsigned long) @@ -306,7 +306,7 @@ int gntdev_map_grant_pages(struct gntdev_grant_map *map) map->grants[i].ref, map->grants[i].domid); gnttab_set_unmap_op(&map->unmap_ops[i], addr, - map->flags, -1 /* handle */); + map->flags, INVALID_GRANT_HANDLE); } } else { /* @@ -332,7 +332,7 @@ int gntdev_map_grant_pages(struct gntdev_grant_map *map) map->grants[i].ref, map->grants[i].domid); gnttab_set_unmap_op(&map->kunmap_ops[i], address, - flags, -1); + flags, INVALID_GRANT_HANDLE); } } @@ -390,7 +390,7 @@ static int __unmap_grant_pages(struct gntdev_grant_map *map, int offset, pr_debug("unmap handle=%d st=%d\n", map->unmap_ops[offset+i].handle, map->unmap_ops[offset+i].status); - map->unmap_ops[offset+i].handle = -1; + map->unmap_ops[offset+i].handle = INVALID_GRANT_HANDLE; } return err; } @@ -406,13 +406,15 @@ static int unmap_grant_pages(struct gntdev_grant_map *map, int offset, * already unmapped some of the grants. Only unmap valid ranges. */ while (pages && !err) { - while (pages && map->unmap_ops[offset].handle == -1) { + while (pages && + map->unmap_ops[offset].handle == INVALID_GRANT_HANDLE) { offset++; pages--; } range = 0; while (range < pages) { - if (map->unmap_ops[offset+range].handle == -1) + if (map->unmap_ops[offset + range].handle == + INVALID_GRANT_HANDLE) break; range++; } diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h index 0b1182a3cf412..cb854df031ce0 100644 --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -50,6 +50,13 @@ #include #include +/* + * Technically there's no reliably invalid grant reference or grant handle, + * so pick the value that is the most unlikely one to be observed valid. + */ +#define INVALID_GRANT_REF ((grant_ref_t)-1) +#define INVALID_GRANT_HANDLE ((grant_handle_t)-1) + #define GNTTAB_RESERVED_XENSTORE 1 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */ diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h index 0b1386073d49b..b94074c827721 100644 --- a/include/xen/xenbus.h +++ b/include/xen/xenbus.h @@ -51,7 +51,6 @@ #define XENBUS_MAX_RING_GRANT_ORDER 4 #define XENBUS_MAX_RING_GRANTS (1U << XENBUS_MAX_RING_GRANT_ORDER) -#define INVALID_GRANT_HANDLE (~0U) /* Register callback to watch this node. */ struct xenbus_watch -- 2.30.2