| Message ID | 20240430164939.925307-17-edgar.iglesias@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
On Tue, 30 Apr 2024, Edgar E. Iglesias wrote: > From: "Edgar E. Iglesias" <edgar.iglesias@amd.com> > > Add a second mapcache for grant mappings. The mapcache for > grants needs to work with XC_PAGE_SIZE granularity since > we can't map larger ranges than what has been granted to us. > > Like with foreign mappings (xen_memory), machines using grants > are expected to initialize the xen_grants MR and map it > into their address-map accordingly. > > Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com> > --- > hw/xen/xen-hvm-common.c | 12 ++- > hw/xen/xen-mapcache.c | 158 +++++++++++++++++++++++++------- > include/hw/xen/xen-hvm-common.h | 3 + > include/sysemu/xen.h | 7 ++ > 4 files changed, 145 insertions(+), 35 deletions(-) > > diff --git a/hw/xen/xen-hvm-common.c b/hw/xen/xen-hvm-common.c > index 0267b88d26..fdec400491 100644 > --- a/hw/xen/xen-hvm-common.c > +++ b/hw/xen/xen-hvm-common.c > @@ -10,12 +10,18 @@ > #include "hw/boards.h" > #include "hw/xen/arch_hvm.h" > > -MemoryRegion xen_memory; > +MemoryRegion xen_memory, xen_grants; > > -/* Check for xen memory. */ > +/* Check for any kind of xen memory, foreign mappings or grants. */ > bool xen_mr_is_memory(MemoryRegion *mr) > { > - return mr == &xen_memory; > + return mr == &xen_memory || mr == &xen_grants; > +} > + > +/* Check specifically for grants. */ > +bool xen_mr_is_grants(MemoryRegion *mr) > +{ > + return mr == &xen_grants; > } > > void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr, > diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c > index 1b32d0c003..96cd68e28d 100644 > --- a/hw/xen/xen-mapcache.c > +++ b/hw/xen/xen-mapcache.c > @@ -14,6 +14,7 @@ > > #include <sys/resource.h> > > +#include "hw/xen/xen-hvm-common.h" > #include "hw/xen/xen_native.h" > #include "qemu/bitmap.h" > > @@ -21,6 +22,8 @@ > #include "sysemu/xen-mapcache.h" > #include "trace.h" > > +#include <xenevtchn.h> > +#include <xengnttab.h> > > #if HOST_LONG_BITS == 32 > # define MCACHE_MAX_SIZE (1UL<<31) /* 2GB Cap */ > @@ -41,6 +44,7 @@ typedef struct MapCacheEntry { > unsigned long *valid_mapping; > uint32_t lock; > #define XEN_MAPCACHE_ENTRY_DUMMY (1 << 0) > +#define XEN_MAPCACHE_ENTRY_GRANT (1 << 1) > uint8_t flags; > hwaddr size; > > @@ -74,6 +78,8 @@ typedef struct MapCache { > } MapCache; > > static MapCache *mapcache; > +static MapCache *mapcache_grants; > +static xengnttab_handle *xen_region_gnttabdev; > > static inline void mapcache_lock(MapCache *mc) > { > @@ -132,6 +138,12 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque) > unsigned long max_mcache_size; > unsigned int bucket_shift; > > + xen_region_gnttabdev = xengnttab_open(NULL, 0); > + if (xen_region_gnttabdev == NULL) { > + error_report("mapcache: Failed to open gnttab device"); > + exit(EXIT_FAILURE); > + } > + > if (HOST_LONG_BITS == 32) { > bucket_shift = 16; > } else { > @@ -160,6 +172,15 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque) > mapcache = xen_map_cache_init_single(f, opaque, > bucket_shift, > max_mcache_size); > + > + /* > + * Grant mappings must use XC_PAGE_SIZE granularity since we can't > + * map anything beyond the number of pages granted to us. > + */ > + mapcache_grants = xen_map_cache_init_single(f, opaque, > + XC_PAGE_SHIFT, > + max_mcache_size); > + > setrlimit(RLIMIT_AS, &rlimit_as); > } > > @@ -169,17 +190,25 @@ static void xen_remap_bucket(MapCache *mc, > hwaddr size, > hwaddr address_index, > bool dummy, > + bool grant, > + bool grant_is_write, > + hwaddr grant_ref, > ram_addr_t ram_offset) Any chance we could pass grant_ref as address_index ? Also instead of grant_is_write we could have a generic is_write that applies to both. I am not sure about this, but instead of bool grant, we could check on address_index using XEN_GRANT_ADDR_OFF? This one might not work. I admit that there is no real advantage on these suggestions except to consolidate the parameters and make them look a bit more similar in the two cases. > { > uint8_t *vaddr_base; > - xen_pfn_t *pfns; > + uint32_t *refs = NULL; > + xen_pfn_t *pfns = NULL; > int *err; > unsigned int i; > hwaddr nb_pfn = size >> XC_PAGE_SHIFT; > > trace_xen_remap_bucket(address_index); > > - pfns = g_new0(xen_pfn_t, nb_pfn); > + if (grant) { > + refs = g_new0(uint32_t, nb_pfn); > + } else { > + pfns = g_new0(xen_pfn_t, nb_pfn); > + } > err = g_new0(int, nb_pfn); > > if (entry->vaddr_base != NULL) { > @@ -208,21 +237,45 @@ static void xen_remap_bucket(MapCache *mc, > g_free(entry->valid_mapping); > entry->valid_mapping = NULL; > > - for (i = 0; i < nb_pfn; i++) { > - pfns[i] = (address_index << (mc->bucket_shift - XC_PAGE_SHIFT)) + i; > + if (grant) { > + for (i = 0; i < nb_pfn; i++) { > + refs[i] = grant_ref + i; > + } > + } else { > + for (i = 0; i < nb_pfn; i++) { > + pfns[i] = (address_index << (mc->bucket_shift - XC_PAGE_SHIFT)) + i; > + } > } > > - /* > - * If the caller has requested the mapping at a specific address use > - * MAP_FIXED to make sure it's honored. > - */ > + entry->flags &= ~XEN_MAPCACHE_ENTRY_GRANT; > + > if (!dummy) { > - vaddr_base = xenforeignmemory_map2(xen_fmem, xen_domid, vaddr, > - PROT_READ | PROT_WRITE, > - vaddr ? MAP_FIXED : 0, > - nb_pfn, pfns, err); > + if (grant) { > + int prot = PROT_READ; > + > + if (grant_is_write) { > + prot |= PROT_WRITE; > + } > + > + entry->flags |= XEN_MAPCACHE_ENTRY_GRANT; > + assert(vaddr == NULL); > + vaddr_base = xengnttab_map_domain_grant_refs(xen_region_gnttabdev, > + nb_pfn, > + xen_domid, refs, > + prot); > + } else { > + /* > + * If the caller has requested the mapping at a specific address use > + * MAP_FIXED to make sure it's honored. > + */ > + vaddr_base = xenforeignmemory_map2(xen_fmem, xen_domid, vaddr, > + PROT_READ | PROT_WRITE, > + vaddr ? MAP_FIXED : 0, > + nb_pfn, pfns, err); > + } > if (vaddr_base == NULL) { > - perror("xenforeignmemory_map2"); > + perror(grant ? "xengnttab_map_domain_grant_refs" > + : "xenforeignmemory_map2"); > exit(-1); > } > } else { > @@ -263,6 +316,7 @@ static void xen_remap_bucket(MapCache *mc, > } > } > > + g_free(refs); > g_free(pfns); > g_free(err); > } > @@ -270,10 +324,12 @@ static void xen_remap_bucket(MapCache *mc, > static uint8_t *xen_map_cache_unlocked(MapCache *mc, > hwaddr phys_addr, hwaddr size, > ram_addr_t ram_offset, > - uint8_t lock, bool dma, bool is_write) > + uint8_t lock, bool dma, > + bool grant, bool is_write) > { > MapCacheEntry *entry, *pentry = NULL, > *free_entry = NULL, *free_pentry = NULL; > + hwaddr grant_ref = phys_addr >> XC_PAGE_SHIFT; > hwaddr address_index; > hwaddr address_offset; > hwaddr cache_size = size; > @@ -342,7 +398,7 @@ tryagain: > entry = g_new0(MapCacheEntry, 1); > pentry->next = entry; > xen_remap_bucket(mc, entry, NULL, cache_size, address_index, dummy, > - ram_offset); > + grant, is_write, grant_ref, ram_offset); > } else if (!entry->lock) { > if (!entry->vaddr_base || entry->paddr_index != address_index || > entry->size != cache_size || > @@ -350,7 +406,7 @@ tryagain: > test_bit_size >> XC_PAGE_SHIFT, > entry->valid_mapping)) { > xen_remap_bucket(mc, entry, NULL, cache_size, address_index, dummy, > - ram_offset); > + grant, is_write, grant_ref, ram_offset); > } > } > > @@ -401,12 +457,28 @@ uint8_t *xen_map_cache(MemoryRegion *mr, > uint8_t lock, bool dma, > bool is_write) > { > + bool grant = xen_mr_is_grants(mr); > + MapCache *mc = grant ? mapcache_grants : mapcache; > uint8_t *p; > > - mapcache_lock(mapcache); > - p = xen_map_cache_unlocked(mapcache, phys_addr, size, ram_addr_offset, > - lock, dma, is_write); > - mapcache_unlock(mapcache); > + if (grant) { > + /* > + * Grants are only supported via address_space_map(). Anything > + * else is considered a user/guest error. > + * > + * QEMU generally doesn't expect these mappings to ever fail, so > + * if this happens we report an error message and abort(). > + */ > + if (!lock) { > + error_report("Trying access a grant reference without mapping it."); > + abort(); > + } > + } > + > + mapcache_lock(mc); > + p = xen_map_cache_unlocked(mc, phys_addr, size, ram_addr_offset, > + lock, dma, grant, is_write); > + mapcache_unlock(mc); > return p; > } > > @@ -451,7 +523,14 @@ static ram_addr_t xen_ram_addr_from_mapcache_single(MapCache *mc, void *ptr) > > ram_addr_t xen_ram_addr_from_mapcache(void *ptr) > { > - return xen_ram_addr_from_mapcache_single(mapcache, ptr); > + ram_addr_t addr; > + > + addr = xen_ram_addr_from_mapcache_single(mapcache, ptr); > + if (addr == RAM_ADDR_INVALID) { > + addr = xen_ram_addr_from_mapcache_single(mapcache_grants, ptr); > + } > + > + return addr; > } > > static void xen_invalidate_map_cache_entry_unlocked(MapCache *mc, > @@ -504,9 +583,14 @@ static void xen_invalidate_map_cache_entry_unlocked(MapCache *mc, > } > > ram_block_notify_remove(entry->vaddr_base, entry->size, entry->size); > - if (munmap(entry->vaddr_base, entry->size) != 0) { > - perror("unmap fails"); > - exit(-1); > + if (entry->flags & XEN_MAPCACHE_ENTRY_GRANT) { > + xengnttab_unmap(xen_region_gnttabdev, entry->vaddr_base, > + (entry->size + mc->bucket_size - 1) >> mc->bucket_shift); Am I getting this right that the + mc->bucket_size - 1 is unnecessary because the bucket size is PAGE_SIZE and we can only map at page granularity? Also can we check for return errors? > + } else { > + if (munmap(entry->vaddr_base, entry->size) != 0) { > + perror("unmap fails"); > + exit(-1); > + } > } > if (pentry) { > pentry->next = entry->next; > @@ -522,14 +606,24 @@ typedef struct XenMapCacheData { > uint8_t *buffer; > } XenMapCacheData; > > +static void xen_invalidate_map_cache_entry_single(MapCache *mc, uint8_t *buffer) > +{ > + mapcache_lock(mc); > + xen_invalidate_map_cache_entry_unlocked(mc, buffer); > + mapcache_unlock(mc); > +} > + > +static void xen_invalidate_map_cache_entry_all(uint8_t *buffer) > +{ > + xen_invalidate_map_cache_entry_single(mapcache, buffer); > + xen_invalidate_map_cache_entry_single(mapcache_grants, buffer); > +} > + > static void xen_invalidate_map_cache_entry_bh(void *opaque) > { > XenMapCacheData *data = opaque; > > - mapcache_lock(mapcache); > - xen_invalidate_map_cache_entry_unlocked(mapcache, data->buffer); > - mapcache_unlock(mapcache); > - > + xen_invalidate_map_cache_entry_all(data->buffer); > aio_co_wake(data->co); > } > > @@ -544,9 +638,7 @@ void coroutine_mixed_fn xen_invalidate_map_cache_entry(uint8_t *buffer) > xen_invalidate_map_cache_entry_bh, &data); > qemu_coroutine_yield(); > } else { > - mapcache_lock(mapcache); > - xen_invalidate_map_cache_entry_unlocked(mapcache, buffer); > - mapcache_unlock(mapcache); > + xen_invalidate_map_cache_entry_all(buffer); > } > } > > @@ -598,6 +690,7 @@ void xen_invalidate_map_cache(void) > bdrv_drain_all(); > > xen_invalidate_map_cache_single(mapcache); > + xen_invalidate_map_cache_single(mapcache_grants); > } > > static uint8_t *xen_replace_cache_entry_unlocked(MapCache *mc, > @@ -639,7 +732,8 @@ static uint8_t *xen_replace_cache_entry_unlocked(MapCache *mc, > trace_xen_replace_cache_entry_dummy(old_phys_addr, new_phys_addr); > > xen_remap_bucket(mc, entry, entry->vaddr_base, > - cache_size, address_index, false, entry->ram_offset); > + cache_size, address_index, false, > + false, false, 0, entry->ram_offset); If I understand correctly, xen_replace_cache_entry_unlocked cannot be called on grants because xen_replace_cache_entry_unlocked is always called on unlocked entries while grants are always locked. Should we have an assert on !entry->lock and/or !(entry->flags & XEN_MAPCACHE_ENTRY_GRANT)? > if (!test_bits(address_offset >> XC_PAGE_SHIFT, > test_bit_size >> XC_PAGE_SHIFT, > entry->valid_mapping)) { > diff --git a/include/hw/xen/xen-hvm-common.h b/include/hw/xen/xen-hvm-common.h > index 65a51aac2e..3d796235dc 100644 > --- a/include/hw/xen/xen-hvm-common.h > +++ b/include/hw/xen/xen-hvm-common.h > @@ -16,6 +16,7 @@ > #include <xen/hvm/ioreq.h> > > extern MemoryRegion xen_memory; > +extern MemoryRegion xen_grants; > extern MemoryListener xen_io_listener; > extern DeviceListener xen_device_listener; > > @@ -29,6 +30,8 @@ extern DeviceListener xen_device_listener; > do { } while (0) > #endif > > +#define XEN_GRANT_ADDR_OFF (1ULL << 63) > + > static inline uint32_t xen_vcpu_eport(shared_iopage_t *shared_page, int i) > { > return shared_page->vcpu_ioreq[i].vp_eport; > diff --git a/include/sysemu/xen.h b/include/sysemu/xen.h > index dc72f83bcb..19dccf4d71 100644 > --- a/include/sysemu/xen.h > +++ b/include/sysemu/xen.h > @@ -35,6 +35,7 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, > struct MemoryRegion *mr, Error **errp); > > bool xen_mr_is_memory(MemoryRegion *mr); > +bool xen_mr_is_grants(MemoryRegion *mr); > > #else /* !CONFIG_XEN_IS_POSSIBLE */ > > @@ -55,6 +56,12 @@ static inline bool xen_mr_is_memory(MemoryRegion *mr) > return false; > } > > +static inline bool xen_mr_is_grants(MemoryRegion *mr) > +{ > + g_assert_not_reached(); > + return false; > +} > + > #endif /* CONFIG_XEN_IS_POSSIBLE */ > > #endif > -- > 2.40.1 >
On Thu, May 2, 2024 at 9:18 PM Stefano Stabellini <sstabellini@kernel.org> wrote: > > On Tue, 30 Apr 2024, Edgar E. Iglesias wrote: > > From: "Edgar E. Iglesias" <edgar.iglesias@amd.com> > > > > Add a second mapcache for grant mappings. The mapcache for > > grants needs to work with XC_PAGE_SIZE granularity since > > we can't map larger ranges than what has been granted to us. > > > > Like with foreign mappings (xen_memory), machines using grants > > are expected to initialize the xen_grants MR and map it > > into their address-map accordingly. > > > > Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com> > > --- > > hw/xen/xen-hvm-common.c | 12 ++- > > hw/xen/xen-mapcache.c | 158 +++++++++++++++++++++++++------- > > include/hw/xen/xen-hvm-common.h | 3 + > > include/sysemu/xen.h | 7 ++ > > 4 files changed, 145 insertions(+), 35 deletions(-) > > > > diff --git a/hw/xen/xen-hvm-common.c b/hw/xen/xen-hvm-common.c > > index 0267b88d26..fdec400491 100644 > > --- a/hw/xen/xen-hvm-common.c > > +++ b/hw/xen/xen-hvm-common.c > > @@ -10,12 +10,18 @@ > > #include "hw/boards.h" > > #include "hw/xen/arch_hvm.h" > > > > -MemoryRegion xen_memory; > > +MemoryRegion xen_memory, xen_grants; > > > > -/* Check for xen memory. */ > > +/* Check for any kind of xen memory, foreign mappings or grants. */ > > bool xen_mr_is_memory(MemoryRegion *mr) > > { > > - return mr == &xen_memory; > > + return mr == &xen_memory || mr == &xen_grants; > > +} > > + > > +/* Check specifically for grants. */ > > +bool xen_mr_is_grants(MemoryRegion *mr) > > +{ > > + return mr == &xen_grants; > > } > > > > void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr, > > diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c > > index 1b32d0c003..96cd68e28d 100644 > > --- a/hw/xen/xen-mapcache.c > > +++ b/hw/xen/xen-mapcache.c > > @@ -14,6 +14,7 @@ > > > > #include <sys/resource.h> > > > > +#include "hw/xen/xen-hvm-common.h" > > #include "hw/xen/xen_native.h" > > #include "qemu/bitmap.h" > > > > @@ -21,6 +22,8 @@ > > #include "sysemu/xen-mapcache.h" > > #include "trace.h" > > > > +#include <xenevtchn.h> > > +#include <xengnttab.h> > > > > #if HOST_LONG_BITS == 32 > > # define MCACHE_MAX_SIZE (1UL<<31) /* 2GB Cap */ > > @@ -41,6 +44,7 @@ typedef struct MapCacheEntry { > > unsigned long *valid_mapping; > > uint32_t lock; > > #define XEN_MAPCACHE_ENTRY_DUMMY (1 << 0) > > +#define XEN_MAPCACHE_ENTRY_GRANT (1 << 1) > > uint8_t flags; > > hwaddr size; > > > > @@ -74,6 +78,8 @@ typedef struct MapCache { > > } MapCache; > > > > static MapCache *mapcache; > > +static MapCache *mapcache_grants; > > +static xengnttab_handle *xen_region_gnttabdev; > > > > static inline void mapcache_lock(MapCache *mc) > > { > > @@ -132,6 +138,12 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque) > > unsigned long max_mcache_size; > > unsigned int bucket_shift; > > > > + xen_region_gnttabdev = xengnttab_open(NULL, 0); > > + if (xen_region_gnttabdev == NULL) { > > + error_report("mapcache: Failed to open gnttab device"); > > + exit(EXIT_FAILURE); > > + } > > + > > if (HOST_LONG_BITS == 32) { > > bucket_shift = 16; > > } else { > > @@ -160,6 +172,15 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque) > > mapcache = xen_map_cache_init_single(f, opaque, > > bucket_shift, > > max_mcache_size); > > + > > + /* > > + * Grant mappings must use XC_PAGE_SIZE granularity since we can't > > + * map anything beyond the number of pages granted to us. > > + */ > > + mapcache_grants = xen_map_cache_init_single(f, opaque, > > + XC_PAGE_SHIFT, > > + max_mcache_size); > > + > > setrlimit(RLIMIT_AS, &rlimit_as); > > } > > > > @@ -169,17 +190,25 @@ static void xen_remap_bucket(MapCache *mc, > > hwaddr size, > > hwaddr address_index, > > bool dummy, > > + bool grant, > > + bool grant_is_write, > > + hwaddr grant_ref, > > ram_addr_t ram_offset) > > Any chance we could pass grant_ref as address_index ? > Yes, good catch :-) grant_ref is already the same as address_index. > Also instead of grant_is_write we could have a generic is_write that > applies to both. Sounds good. > > I am not sure about this, but instead of bool grant, we could check on > address_index using XEN_GRANT_ADDR_OFF? This one might not work. > Yeah, this won't work since we're only getting the offset into the xen_grants memory region. > I admit that there is no real advantage on these suggestions except to > consolidate the parameters and make them look a bit more similar in the > two cases. > > > > > { > > uint8_t *vaddr_base; > > - xen_pfn_t *pfns; > > + uint32_t *refs = NULL; > > + xen_pfn_t *pfns = NULL; > > int *err; > > unsigned int i; > > hwaddr nb_pfn = size >> XC_PAGE_SHIFT; > > > > trace_xen_remap_bucket(address_index); > > > > - pfns = g_new0(xen_pfn_t, nb_pfn); > > + if (grant) { > > + refs = g_new0(uint32_t, nb_pfn); > > + } else { > > + pfns = g_new0(xen_pfn_t, nb_pfn); > > + } > > err = g_new0(int, nb_pfn); > > > > if (entry->vaddr_base != NULL) { > > @@ -208,21 +237,45 @@ static void xen_remap_bucket(MapCache *mc, > > g_free(entry->valid_mapping); > > entry->valid_mapping = NULL; > > > > - for (i = 0; i < nb_pfn; i++) { > > - pfns[i] = (address_index << (mc->bucket_shift - XC_PAGE_SHIFT)) + i; > > + if (grant) { > > + for (i = 0; i < nb_pfn; i++) { > > + refs[i] = grant_ref + i; > > + } > > + } else { > > + for (i = 0; i < nb_pfn; i++) { > > + pfns[i] = (address_index << (mc->bucket_shift - XC_PAGE_SHIFT)) + i; > > + } > > } > > > > - /* > > - * If the caller has requested the mapping at a specific address use > > - * MAP_FIXED to make sure it's honored. > > - */ > > + entry->flags &= ~XEN_MAPCACHE_ENTRY_GRANT; > > + > > if (!dummy) { > > - vaddr_base = xenforeignmemory_map2(xen_fmem, xen_domid, vaddr, > > - PROT_READ | PROT_WRITE, > > - vaddr ? MAP_FIXED : 0, > > - nb_pfn, pfns, err); > > + if (grant) { > > + int prot = PROT_READ; > > + > > + if (grant_is_write) { > > + prot |= PROT_WRITE; > > + } > > + > > + entry->flags |= XEN_MAPCACHE_ENTRY_GRANT; > > + assert(vaddr == NULL); > > + vaddr_base = xengnttab_map_domain_grant_refs(xen_region_gnttabdev, > > + nb_pfn, > > + xen_domid, refs, > > + prot); > > + } else { > > + /* > > + * If the caller has requested the mapping at a specific address use > > + * MAP_FIXED to make sure it's honored. > > + */ > > + vaddr_base = xenforeignmemory_map2(xen_fmem, xen_domid, vaddr, > > + PROT_READ | PROT_WRITE, > > + vaddr ? MAP_FIXED : 0, > > + nb_pfn, pfns, err); > > + } > > if (vaddr_base == NULL) { > > - perror("xenforeignmemory_map2"); > > + perror(grant ? "xengnttab_map_domain_grant_refs" > > + : "xenforeignmemory_map2"); > > exit(-1); > > } > > } else { > > @@ -263,6 +316,7 @@ static void xen_remap_bucket(MapCache *mc, > > } > > } > > > > + g_free(refs); > > g_free(pfns); > > g_free(err); > > } > > @@ -270,10 +324,12 @@ static void xen_remap_bucket(MapCache *mc, > > static uint8_t *xen_map_cache_unlocked(MapCache *mc, > > hwaddr phys_addr, hwaddr size, > > ram_addr_t ram_offset, > > - uint8_t lock, bool dma, bool is_write) > > + uint8_t lock, bool dma, > > + bool grant, bool is_write) > > { > > MapCacheEntry *entry, *pentry = NULL, > > *free_entry = NULL, *free_pentry = NULL; > > + hwaddr grant_ref = phys_addr >> XC_PAGE_SHIFT; > > hwaddr address_index; > > hwaddr address_offset; > > hwaddr cache_size = size; > > @@ -342,7 +398,7 @@ tryagain: > > entry = g_new0(MapCacheEntry, 1); > > pentry->next = entry; > > xen_remap_bucket(mc, entry, NULL, cache_size, address_index, dummy, > > - ram_offset); > > + grant, is_write, grant_ref, ram_offset); > > } else if (!entry->lock) { > > if (!entry->vaddr_base || entry->paddr_index != address_index || > > entry->size != cache_size || > > @@ -350,7 +406,7 @@ tryagain: > > test_bit_size >> XC_PAGE_SHIFT, > > entry->valid_mapping)) { > > xen_remap_bucket(mc, entry, NULL, cache_size, address_index, dummy, > > - ram_offset); > > + grant, is_write, grant_ref, ram_offset); > > } > > } > > > > @@ -401,12 +457,28 @@ uint8_t *xen_map_cache(MemoryRegion *mr, > > uint8_t lock, bool dma, > > bool is_write) > > { > > + bool grant = xen_mr_is_grants(mr); > > + MapCache *mc = grant ? mapcache_grants : mapcache; > > uint8_t *p; > > > > - mapcache_lock(mapcache); > > - p = xen_map_cache_unlocked(mapcache, phys_addr, size, ram_addr_offset, > > - lock, dma, is_write); > > - mapcache_unlock(mapcache); > > + if (grant) { > > + /* > > + * Grants are only supported via address_space_map(). Anything > > + * else is considered a user/guest error. > > + * > > + * QEMU generally doesn't expect these mappings to ever fail, so > > + * if this happens we report an error message and abort(). > > + */ > > + if (!lock) { > > + error_report("Trying access a grant reference without mapping it."); > > + abort(); > > + } > > + } > > + > > + mapcache_lock(mc); > > + p = xen_map_cache_unlocked(mc, phys_addr, size, ram_addr_offset, > > + lock, dma, grant, is_write); > > + mapcache_unlock(mc); > > return p; > > } > > > > @@ -451,7 +523,14 @@ static ram_addr_t xen_ram_addr_from_mapcache_single(MapCache *mc, void *ptr) > > > > ram_addr_t xen_ram_addr_from_mapcache(void *ptr) > > { > > - return xen_ram_addr_from_mapcache_single(mapcache, ptr); > > + ram_addr_t addr; > > + > > + addr = xen_ram_addr_from_mapcache_single(mapcache, ptr); > > + if (addr == RAM_ADDR_INVALID) { > > + addr = xen_ram_addr_from_mapcache_single(mapcache_grants, ptr); > > + } > > + > > + return addr; > > } > > > > static void xen_invalidate_map_cache_entry_unlocked(MapCache *mc, > > @@ -504,9 +583,14 @@ static void xen_invalidate_map_cache_entry_unlocked(MapCache *mc, > > } > > > > ram_block_notify_remove(entry->vaddr_base, entry->size, entry->size); > > - if (munmap(entry->vaddr_base, entry->size) != 0) { > > - perror("unmap fails"); > > - exit(-1); > > + if (entry->flags & XEN_MAPCACHE_ENTRY_GRANT) { > > + xengnttab_unmap(xen_region_gnttabdev, entry->vaddr_base, > > + (entry->size + mc->bucket_size - 1) >> mc->bucket_shift); > > Am I getting this right that the + mc->bucket_size - 1 is unnecessary > because the bucket size is PAGE_SIZE and we can only map at page > granularity? > Yes, you're right. I'll fix this up in the next version. > Also can we check for return errors? Yes, I'll add error checking. > > > > + } else { > > + if (munmap(entry->vaddr_base, entry->size) != 0) { > > + perror("unmap fails"); > > + exit(-1); > > + } > > } > > if (pentry) { > > pentry->next = entry->next; > > @@ -522,14 +606,24 @@ typedef struct XenMapCacheData { > > uint8_t *buffer; > > } XenMapCacheData; > > > > +static void xen_invalidate_map_cache_entry_single(MapCache *mc, uint8_t *buffer) > > +{ > > + mapcache_lock(mc); > > + xen_invalidate_map_cache_entry_unlocked(mc, buffer); > > + mapcache_unlock(mc); > > +} > > + > > +static void xen_invalidate_map_cache_entry_all(uint8_t *buffer) > > +{ > > + xen_invalidate_map_cache_entry_single(mapcache, buffer); > > + xen_invalidate_map_cache_entry_single(mapcache_grants, buffer); > > +} > > + > > static void xen_invalidate_map_cache_entry_bh(void *opaque) > > { > > XenMapCacheData *data = opaque; > > > > - mapcache_lock(mapcache); > > - xen_invalidate_map_cache_entry_unlocked(mapcache, data->buffer); > > - mapcache_unlock(mapcache); > > - > > + xen_invalidate_map_cache_entry_all(data->buffer); > > aio_co_wake(data->co); > > } > > > > @@ -544,9 +638,7 @@ void coroutine_mixed_fn xen_invalidate_map_cache_entry(uint8_t *buffer) > > xen_invalidate_map_cache_entry_bh, &data); > > qemu_coroutine_yield(); > > } else { > > - mapcache_lock(mapcache); > > - xen_invalidate_map_cache_entry_unlocked(mapcache, buffer); > > - mapcache_unlock(mapcache); > > + xen_invalidate_map_cache_entry_all(buffer); > > } > > } > > > > @@ -598,6 +690,7 @@ void xen_invalidate_map_cache(void) > > bdrv_drain_all(); > > > > xen_invalidate_map_cache_single(mapcache); > > + xen_invalidate_map_cache_single(mapcache_grants); > > } > > > > static uint8_t *xen_replace_cache_entry_unlocked(MapCache *mc, > > @@ -639,7 +732,8 @@ static uint8_t *xen_replace_cache_entry_unlocked(MapCache *mc, > > trace_xen_replace_cache_entry_dummy(old_phys_addr, new_phys_addr); > > > > xen_remap_bucket(mc, entry, entry->vaddr_base, > > - cache_size, address_index, false, entry->ram_offset); > > + cache_size, address_index, false, > > + false, false, 0, entry->ram_offset); > > If I understand correctly, xen_replace_cache_entry_unlocked cannot be > called on grants because xen_replace_cache_entry_unlocked is always > called on unlocked entries while grants are always locked. Should we > have an assert on !entry->lock and/or !(entry->flags & XEN_MAPCACHE_ENTRY_GRANT)? > Sounds good, I'll add this in the next version as well. > > > > if (!test_bits(address_offset >> XC_PAGE_SHIFT, > > test_bit_size >> XC_PAGE_SHIFT, > > entry->valid_mapping)) { > > diff --git a/include/hw/xen/xen-hvm-common.h b/include/hw/xen/xen-hvm-common.h > > index 65a51aac2e..3d796235dc 100644 > > --- a/include/hw/xen/xen-hvm-common.h > > +++ b/include/hw/xen/xen-hvm-common.h > > @@ -16,6 +16,7 @@ > > #include <xen/hvm/ioreq.h> > > > > extern MemoryRegion xen_memory; > > +extern MemoryRegion xen_grants; > > extern MemoryListener xen_io_listener; > > extern DeviceListener xen_device_listener; > > > > @@ -29,6 +30,8 @@ extern DeviceListener xen_device_listener; > > do { } while (0) > > #endif > > > > +#define XEN_GRANT_ADDR_OFF (1ULL << 63) > > + > > static inline uint32_t xen_vcpu_eport(shared_iopage_t *shared_page, int i) > > { > > return shared_page->vcpu_ioreq[i].vp_eport; > > diff --git a/include/sysemu/xen.h b/include/sysemu/xen.h > > index dc72f83bcb..19dccf4d71 100644 > > --- a/include/sysemu/xen.h > > +++ b/include/sysemu/xen.h > > @@ -35,6 +35,7 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, > > struct MemoryRegion *mr, Error **errp); > > > > bool xen_mr_is_memory(MemoryRegion *mr); > > +bool xen_mr_is_grants(MemoryRegion *mr); > > > > #else /* !CONFIG_XEN_IS_POSSIBLE */ > > > > @@ -55,6 +56,12 @@ static inline bool xen_mr_is_memory(MemoryRegion *mr) > > return false; > > } > > > > +static inline bool xen_mr_is_grants(MemoryRegion *mr) > > +{ > > + g_assert_not_reached(); > > + return false; > > +} > > + > > #endif /* CONFIG_XEN_IS_POSSIBLE */ > > > > #endif > > -- > > 2.40.1 > >
diff --git a/hw/xen/xen-hvm-common.c b/hw/xen/xen-hvm-common.c index 0267b88d26..fdec400491 100644 --- a/hw/xen/xen-hvm-common.c +++ b/hw/xen/xen-hvm-common.c @@ -10,12 +10,18 @@ #include "hw/boards.h" #include "hw/xen/arch_hvm.h" -MemoryRegion xen_memory; +MemoryRegion xen_memory, xen_grants; -/* Check for xen memory. */ +/* Check for any kind of xen memory, foreign mappings or grants. */ bool xen_mr_is_memory(MemoryRegion *mr) { - return mr == &xen_memory; + return mr == &xen_memory || mr == &xen_grants; +} + +/* Check specifically for grants. */ +bool xen_mr_is_grants(MemoryRegion *mr) +{ + return mr == &xen_grants; } void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr, diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c index 1b32d0c003..96cd68e28d 100644 --- a/hw/xen/xen-mapcache.c +++ b/hw/xen/xen-mapcache.c @@ -14,6 +14,7 @@ #include <sys/resource.h> +#include "hw/xen/xen-hvm-common.h" #include "hw/xen/xen_native.h" #include "qemu/bitmap.h" @@ -21,6 +22,8 @@ #include "sysemu/xen-mapcache.h" #include "trace.h" +#include <xenevtchn.h> +#include <xengnttab.h> #if HOST_LONG_BITS == 32 # define MCACHE_MAX_SIZE (1UL<<31) /* 2GB Cap */ @@ -41,6 +44,7 @@ typedef struct MapCacheEntry { unsigned long *valid_mapping; uint32_t lock; #define XEN_MAPCACHE_ENTRY_DUMMY (1 << 0) +#define XEN_MAPCACHE_ENTRY_GRANT (1 << 1) uint8_t flags; hwaddr size; @@ -74,6 +78,8 @@ typedef struct MapCache { } MapCache; static MapCache *mapcache; +static MapCache *mapcache_grants; +static xengnttab_handle *xen_region_gnttabdev; static inline void mapcache_lock(MapCache *mc) { @@ -132,6 +138,12 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque) unsigned long max_mcache_size; unsigned int bucket_shift; + xen_region_gnttabdev = xengnttab_open(NULL, 0); + if (xen_region_gnttabdev == NULL) { + error_report("mapcache: Failed to open gnttab device"); + exit(EXIT_FAILURE); + } + if (HOST_LONG_BITS == 32) { bucket_shift = 16; } else { @@ -160,6 +172,15 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque) mapcache = xen_map_cache_init_single(f, opaque, bucket_shift, max_mcache_size); + + /* + * Grant mappings must use XC_PAGE_SIZE granularity since we can't + * map anything beyond the number of pages granted to us. + */ + mapcache_grants = xen_map_cache_init_single(f, opaque, + XC_PAGE_SHIFT, + max_mcache_size); + setrlimit(RLIMIT_AS, &rlimit_as); } @@ -169,17 +190,25 @@ static void xen_remap_bucket(MapCache *mc, hwaddr size, hwaddr address_index, bool dummy, + bool grant, + bool grant_is_write, + hwaddr grant_ref, ram_addr_t ram_offset) { uint8_t *vaddr_base; - xen_pfn_t *pfns; + uint32_t *refs = NULL; + xen_pfn_t *pfns = NULL; int *err; unsigned int i; hwaddr nb_pfn = size >> XC_PAGE_SHIFT; trace_xen_remap_bucket(address_index); - pfns = g_new0(xen_pfn_t, nb_pfn); + if (grant) { + refs = g_new0(uint32_t, nb_pfn); + } else { + pfns = g_new0(xen_pfn_t, nb_pfn); + } err = g_new0(int, nb_pfn); if (entry->vaddr_base != NULL) { @@ -208,21 +237,45 @@ static void xen_remap_bucket(MapCache *mc, g_free(entry->valid_mapping); entry->valid_mapping = NULL; - for (i = 0; i < nb_pfn; i++) { - pfns[i] = (address_index << (mc->bucket_shift - XC_PAGE_SHIFT)) + i; + if (grant) { + for (i = 0; i < nb_pfn; i++) { + refs[i] = grant_ref + i; + } + } else { + for (i = 0; i < nb_pfn; i++) { + pfns[i] = (address_index << (mc->bucket_shift - XC_PAGE_SHIFT)) + i; + } } - /* - * If the caller has requested the mapping at a specific address use - * MAP_FIXED to make sure it's honored. - */ + entry->flags &= ~XEN_MAPCACHE_ENTRY_GRANT; + if (!dummy) { - vaddr_base = xenforeignmemory_map2(xen_fmem, xen_domid, vaddr, - PROT_READ | PROT_WRITE, - vaddr ? MAP_FIXED : 0, - nb_pfn, pfns, err); + if (grant) { + int prot = PROT_READ; + + if (grant_is_write) { + prot |= PROT_WRITE; + } + + entry->flags |= XEN_MAPCACHE_ENTRY_GRANT; + assert(vaddr == NULL); + vaddr_base = xengnttab_map_domain_grant_refs(xen_region_gnttabdev, + nb_pfn, + xen_domid, refs, + prot); + } else { + /* + * If the caller has requested the mapping at a specific address use + * MAP_FIXED to make sure it's honored. + */ + vaddr_base = xenforeignmemory_map2(xen_fmem, xen_domid, vaddr, + PROT_READ | PROT_WRITE, + vaddr ? MAP_FIXED : 0, + nb_pfn, pfns, err); + } if (vaddr_base == NULL) { - perror("xenforeignmemory_map2"); + perror(grant ? "xengnttab_map_domain_grant_refs" + : "xenforeignmemory_map2"); exit(-1); } } else { @@ -263,6 +316,7 @@ static void xen_remap_bucket(MapCache *mc, } } + g_free(refs); g_free(pfns); g_free(err); } @@ -270,10 +324,12 @@ static void xen_remap_bucket(MapCache *mc, static uint8_t *xen_map_cache_unlocked(MapCache *mc, hwaddr phys_addr, hwaddr size, ram_addr_t ram_offset, - uint8_t lock, bool dma, bool is_write) + uint8_t lock, bool dma, + bool grant, bool is_write) { MapCacheEntry *entry, *pentry = NULL, *free_entry = NULL, *free_pentry = NULL; + hwaddr grant_ref = phys_addr >> XC_PAGE_SHIFT; hwaddr address_index; hwaddr address_offset; hwaddr cache_size = size; @@ -342,7 +398,7 @@ tryagain: entry = g_new0(MapCacheEntry, 1); pentry->next = entry; xen_remap_bucket(mc, entry, NULL, cache_size, address_index, dummy, - ram_offset); + grant, is_write, grant_ref, ram_offset); } else if (!entry->lock) { if (!entry->vaddr_base || entry->paddr_index != address_index || entry->size != cache_size || @@ -350,7 +406,7 @@ tryagain: test_bit_size >> XC_PAGE_SHIFT, entry->valid_mapping)) { xen_remap_bucket(mc, entry, NULL, cache_size, address_index, dummy, - ram_offset); + grant, is_write, grant_ref, ram_offset); } } @@ -401,12 +457,28 @@ uint8_t *xen_map_cache(MemoryRegion *mr, uint8_t lock, bool dma, bool is_write) { + bool grant = xen_mr_is_grants(mr); + MapCache *mc = grant ? mapcache_grants : mapcache; uint8_t *p; - mapcache_lock(mapcache); - p = xen_map_cache_unlocked(mapcache, phys_addr, size, ram_addr_offset, - lock, dma, is_write); - mapcache_unlock(mapcache); + if (grant) { + /* + * Grants are only supported via address_space_map(). Anything + * else is considered a user/guest error. + * + * QEMU generally doesn't expect these mappings to ever fail, so + * if this happens we report an error message and abort(). + */ + if (!lock) { + error_report("Trying access a grant reference without mapping it."); + abort(); + } + } + + mapcache_lock(mc); + p = xen_map_cache_unlocked(mc, phys_addr, size, ram_addr_offset, + lock, dma, grant, is_write); + mapcache_unlock(mc); return p; } @@ -451,7 +523,14 @@ static ram_addr_t xen_ram_addr_from_mapcache_single(MapCache *mc, void *ptr) ram_addr_t xen_ram_addr_from_mapcache(void *ptr) { - return xen_ram_addr_from_mapcache_single(mapcache, ptr); + ram_addr_t addr; + + addr = xen_ram_addr_from_mapcache_single(mapcache, ptr); + if (addr == RAM_ADDR_INVALID) { + addr = xen_ram_addr_from_mapcache_single(mapcache_grants, ptr); + } + + return addr; } static void xen_invalidate_map_cache_entry_unlocked(MapCache *mc, @@ -504,9 +583,14 @@ static void xen_invalidate_map_cache_entry_unlocked(MapCache *mc, } ram_block_notify_remove(entry->vaddr_base, entry->size, entry->size); - if (munmap(entry->vaddr_base, entry->size) != 0) { - perror("unmap fails"); - exit(-1); + if (entry->flags & XEN_MAPCACHE_ENTRY_GRANT) { + xengnttab_unmap(xen_region_gnttabdev, entry->vaddr_base, + (entry->size + mc->bucket_size - 1) >> mc->bucket_shift); + } else { + if (munmap(entry->vaddr_base, entry->size) != 0) { + perror("unmap fails"); + exit(-1); + } } if (pentry) { pentry->next = entry->next; @@ -522,14 +606,24 @@ typedef struct XenMapCacheData { uint8_t *buffer; } XenMapCacheData; +static void xen_invalidate_map_cache_entry_single(MapCache *mc, uint8_t *buffer) +{ + mapcache_lock(mc); + xen_invalidate_map_cache_entry_unlocked(mc, buffer); + mapcache_unlock(mc); +} + +static void xen_invalidate_map_cache_entry_all(uint8_t *buffer) +{ + xen_invalidate_map_cache_entry_single(mapcache, buffer); + xen_invalidate_map_cache_entry_single(mapcache_grants, buffer); +} + static void xen_invalidate_map_cache_entry_bh(void *opaque) { XenMapCacheData *data = opaque; - mapcache_lock(mapcache); - xen_invalidate_map_cache_entry_unlocked(mapcache, data->buffer); - mapcache_unlock(mapcache); - + xen_invalidate_map_cache_entry_all(data->buffer); aio_co_wake(data->co); } @@ -544,9 +638,7 @@ void coroutine_mixed_fn xen_invalidate_map_cache_entry(uint8_t *buffer) xen_invalidate_map_cache_entry_bh, &data); qemu_coroutine_yield(); } else { - mapcache_lock(mapcache); - xen_invalidate_map_cache_entry_unlocked(mapcache, buffer); - mapcache_unlock(mapcache); + xen_invalidate_map_cache_entry_all(buffer); } } @@ -598,6 +690,7 @@ void xen_invalidate_map_cache(void) bdrv_drain_all(); xen_invalidate_map_cache_single(mapcache); + xen_invalidate_map_cache_single(mapcache_grants); } static uint8_t *xen_replace_cache_entry_unlocked(MapCache *mc, @@ -639,7 +732,8 @@ static uint8_t *xen_replace_cache_entry_unlocked(MapCache *mc, trace_xen_replace_cache_entry_dummy(old_phys_addr, new_phys_addr); xen_remap_bucket(mc, entry, entry->vaddr_base, - cache_size, address_index, false, entry->ram_offset); + cache_size, address_index, false, + false, false, 0, entry->ram_offset); if (!test_bits(address_offset >> XC_PAGE_SHIFT, test_bit_size >> XC_PAGE_SHIFT, entry->valid_mapping)) { diff --git a/include/hw/xen/xen-hvm-common.h b/include/hw/xen/xen-hvm-common.h index 65a51aac2e..3d796235dc 100644 --- a/include/hw/xen/xen-hvm-common.h +++ b/include/hw/xen/xen-hvm-common.h @@ -16,6 +16,7 @@ #include <xen/hvm/ioreq.h> extern MemoryRegion xen_memory; +extern MemoryRegion xen_grants; extern MemoryListener xen_io_listener; extern DeviceListener xen_device_listener; @@ -29,6 +30,8 @@ extern DeviceListener xen_device_listener; do { } while (0) #endif +#define XEN_GRANT_ADDR_OFF (1ULL << 63) + static inline uint32_t xen_vcpu_eport(shared_iopage_t *shared_page, int i) { return shared_page->vcpu_ioreq[i].vp_eport; diff --git a/include/sysemu/xen.h b/include/sysemu/xen.h index dc72f83bcb..19dccf4d71 100644 --- a/include/sysemu/xen.h +++ b/include/sysemu/xen.h @@ -35,6 +35,7 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, struct MemoryRegion *mr, Error **errp); bool xen_mr_is_memory(MemoryRegion *mr); +bool xen_mr_is_grants(MemoryRegion *mr); #else /* !CONFIG_XEN_IS_POSSIBLE */ @@ -55,6 +56,12 @@ static inline bool xen_mr_is_memory(MemoryRegion *mr) return false; } +static inline bool xen_mr_is_grants(MemoryRegion *mr) +{ + g_assert_not_reached(); + return false; +} + #endif /* CONFIG_XEN_IS_POSSIBLE */ #endif