This new call is trying to update a requested map cache entry according to the changes in the physmap. The call is searching for the entry, unmaps it and maps again at the same place using a new guest address. If the mapping is dummy this call will make it real.
This function makes use of a new xenforeignmemory_map2() call with an extended interface that was recently introduced in libxenforeignmemory [1]. [1] https://www.mail-archive.com/xen-devel@lists.xen.org/msg113007.html Signed-off-by: Igor Druzhinin <igor.druzhi...@citrix.com> --- configure | 18 ++++++++++ hw/i386/xen/xen-mapcache.c | 79 ++++++++++++++++++++++++++++++++++++++----- include/hw/xen/xen_common.h | 7 ++++ include/sysemu/xen-mapcache.h | 11 +++++- 4 files changed, 106 insertions(+), 9 deletions(-) diff --git a/configure b/configure index c571ad1..ad6156b 100755 --- a/configure +++ b/configure @@ -2021,6 +2021,24 @@ EOF # Xen unstable elif cat > $TMPC <<EOF && +#undef XC_WANT_COMPAT_MAP_FOREIGN_API +#include <xenforeignmemory.h> +int main(void) { + xenforeignmemory_handle *xfmem; + + xfmem = xenforeignmemory_open(0, 0); + xenforeignmemory_map2(xfmem, 0, 0, 0, 0, 0, 0, 0); + + return 0; +} +EOF + compile_prog "" "$xen_libs -lxendevicemodel $xen_stable_libs" + then + xen_stable_libs="-lxendevicemodel $xen_stable_libs" + xen_ctrl_version=41000 + xen=yes + elif + cat > $TMPC <<EOF && #undef XC_WANT_COMPAT_DEVICEMODEL_API #define __XEN_TOOLS__ #include <xendevicemodel.h> diff --git a/hw/i386/xen/xen-mapcache.c b/hw/i386/xen/xen-mapcache.c index cd4e746..a988be7 100644 --- a/hw/i386/xen/xen-mapcache.c +++ b/hw/i386/xen/xen-mapcache.c @@ -151,6 +151,7 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque) } static void xen_remap_bucket(MapCacheEntry *entry, + void *vaddr, hwaddr size, hwaddr address_index, bool dummy) @@ -167,7 +168,9 @@ static void xen_remap_bucket(MapCacheEntry *entry, err = g_malloc0(nb_pfn * sizeof (int)); if (entry->vaddr_base != NULL) { - ram_block_notify_remove(entry->vaddr_base, entry->size); + if (entry->vaddr_base != vaddr) { + ram_block_notify_remove(entry->vaddr_base, entry->size); + } if (munmap(entry->vaddr_base, entry->size) != 0) { perror("unmap fails"); exit(-1); @@ -181,11 +184,11 @@ static void xen_remap_bucket(MapCacheEntry *entry, } if (!dummy) { - vaddr_base = xenforeignmemory_map(xen_fmem, xen_domid, - PROT_READ|PROT_WRITE, + vaddr_base = xenforeignmemory_map2(xen_fmem, xen_domid, vaddr, + PROT_READ|PROT_WRITE, 0, nb_pfn, pfns, err); if (vaddr_base == NULL) { - perror("xenforeignmemory_map"); + perror("xenforeignmemory_map2"); exit(-1); } entry->flags &= ~(XEN_MAPCACHE_ENTRY_DUMMY); @@ -194,7 +197,7 @@ static void xen_remap_bucket(MapCacheEntry *entry, * We create dummy mappings where we are unable to create a foreign * mapping immediately due to certain circumstances (i.e. on resume now) */ - vaddr_base = mmap(NULL, size, PROT_READ|PROT_WRITE, + vaddr_base = mmap(vaddr, size, PROT_READ|PROT_WRITE, MAP_ANON|MAP_SHARED, -1, 0); if (vaddr_base == NULL) { perror("mmap"); @@ -203,13 +206,16 @@ static void xen_remap_bucket(MapCacheEntry *entry, entry->flags |= XEN_MAPCACHE_ENTRY_DUMMY; } + if (entry->vaddr_base == NULL || entry->vaddr_base != vaddr) { + ram_block_notify_add(vaddr_base, size); + } + entry->vaddr_base = vaddr_base; entry->paddr_index = address_index; entry->size = size; entry->valid_mapping = (unsigned long *) g_malloc0(sizeof(unsigned long) * BITS_TO_LONGS(size >> XC_PAGE_SHIFT)); - ram_block_notify_add(entry->vaddr_base, entry->size); bitmap_zero(entry->valid_mapping, nb_pfn); for (i = 0; i < nb_pfn; i++) { if (!err[i]) { @@ -282,14 +288,14 @@ tryagain: if (!entry) { entry = g_malloc0(sizeof (MapCacheEntry)); pentry->next = entry; - xen_remap_bucket(entry, cache_size, address_index, dummy); + xen_remap_bucket(entry, NULL, cache_size, address_index, dummy); } else if (!entry->lock) { if (!entry->vaddr_base || entry->paddr_index != address_index || entry->size != cache_size || !test_bits(address_offset >> XC_PAGE_SHIFT, test_bit_size >> XC_PAGE_SHIFT, entry->valid_mapping)) { - xen_remap_bucket(entry, cache_size, address_index, dummy); + xen_remap_bucket(entry, NULL, cache_size, address_index, dummy); } } @@ -486,3 +492,60 @@ void xen_invalidate_map_cache(void) mapcache_unlock(); } + +static uint8_t *xen_replace_cache_entry_unlocked(hwaddr old_phys_addr, + hwaddr new_phys_addr, + hwaddr size) +{ + MapCacheEntry *entry; + hwaddr address_index; + hwaddr address_offset; + hwaddr cache_size = size; + hwaddr test_bit_size; + + address_index = old_phys_addr >> MCACHE_BUCKET_SHIFT; + address_offset = old_phys_addr & (MCACHE_BUCKET_SIZE - 1); + + assert(size); + /* test_bit_size is always a multiple of XC_PAGE_SIZE */ + test_bit_size = size + (old_phys_addr & (XC_PAGE_SIZE - 1)); + if (test_bit_size % XC_PAGE_SIZE) { + test_bit_size += XC_PAGE_SIZE - (test_bit_size % XC_PAGE_SIZE); + } + cache_size = size + address_offset; + if (cache_size % MCACHE_BUCKET_SIZE) { + cache_size += MCACHE_BUCKET_SIZE - (cache_size % MCACHE_BUCKET_SIZE); + } + + entry = &mapcache->entry[address_index % mapcache->nr_buckets]; + while (entry && !(entry->paddr_index == address_index && entry->size == cache_size)) { + entry = entry->next; + } + if (!entry) { + DPRINTF("Trying to update an entry for %lx that is not in the mapcache!\n", phys_addr); + return NULL; + } + + address_index = new_phys_addr >> MCACHE_BUCKET_SHIFT; + address_offset = new_phys_addr & (MCACHE_BUCKET_SIZE - 1); + + xen_remap_bucket(entry, entry->vaddr_base, cache_size, address_index, false); + if(!test_bits(address_offset >> XC_PAGE_SHIFT, + test_bit_size >> XC_PAGE_SHIFT, + entry->valid_mapping)) { + DPRINTF("Unable to update an entry for %lx in the mapcache!\n", phys_addr); + return NULL; + } + + return entry->vaddr_base + address_offset; +} + +uint8_t *xen_replace_cache_entry(hwaddr old_phys_addr, hwaddr new_phys_addr, hwaddr size) +{ + uint8_t *p; + + mapcache_lock(); + p = xen_replace_cache_entry_unlocked(old_phys_addr, new_phys_addr, size); + mapcache_unlock(); + return p; +} diff --git a/include/hw/xen/xen_common.h b/include/hw/xen/xen_common.h index e00ddd7..70a5cad 100644 --- a/include/hw/xen/xen_common.h +++ b/include/hw/xen/xen_common.h @@ -78,6 +78,13 @@ static inline void *xenforeignmemory_map(xc_interface *h, uint32_t dom, extern xenforeignmemory_handle *xen_fmem; +#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 41000 + +#define xenforeignmemory_map2(h, d, a, p, f, ps, ar, e) \ + xenforeignmemory_map(h, d, p, ps, ar, e) + +#endif + #if CONFIG_XEN_CTRL_INTERFACE_VERSION < 40900 typedef xc_interface xendevicemodel_handle; diff --git a/include/sysemu/xen-mapcache.h b/include/sysemu/xen-mapcache.h index 01daaad..b38962c 100644 --- a/include/sysemu/xen-mapcache.h +++ b/include/sysemu/xen-mapcache.h @@ -21,7 +21,9 @@ uint8_t *xen_map_cache(hwaddr phys_addr, hwaddr size, ram_addr_t xen_ram_addr_from_mapcache(void *ptr); void xen_invalidate_map_cache_entry(uint8_t *buffer); void xen_invalidate_map_cache(void); - +uint8_t *xen_replace_cache_entry(hwaddr old_phys_addr, + hwaddr new_phys_addr, + hwaddr size); #else static inline void xen_map_cache_init(phys_offset_to_gaddr_t f, @@ -50,6 +52,13 @@ static inline void xen_invalidate_map_cache(void) { } +uint8_t *xen_replace_cache_entry(hwaddr old_phys_addr, + hwaddr new_phys_addr, + hwaddr size) +{ + abort(); +} + #endif #endif /* XEN_MAPCACHE_H */ -- 2.7.4