| Message ID | 1499183267-28623-3-git-send-email-igor.druzhinin@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> -----Original Message----- > From: Igor Druzhinin > Sent: 04 July 2017 16:48 > To: xen-devel@lists.xenproject.org; qemu-devel@nongnu.org > Cc: Igor Druzhinin <igor.druzhinin@citrix.com>; sstabellini@kernel.org; > Anthony Perard <anthony.perard@citrix.com>; Paul Durrant > <Paul.Durrant@citrix.com>; pbonzini@redhat.com > Subject: [PATCH v2 2/4] xen/mapcache: add an ability to create dummy > mappings > > Dummys are simple anonymous mappings that are placed instead > of regular foreign mappings in certain situations when we need > to postpone the actual mapping but still have to give a > memory region to QEMU to play with. > > This is planned to be used for restore on Xen. > > Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> > --- > hw/i386/xen/xen-mapcache.c | 40 > ++++++++++++++++++++++++++++++++-------- > 1 file changed, 32 insertions(+), 8 deletions(-) > > diff --git a/hw/i386/xen/xen-mapcache.c b/hw/i386/xen/xen-mapcache.c > index e60156c..cd4e746 100644 > --- a/hw/i386/xen/xen-mapcache.c > +++ b/hw/i386/xen/xen-mapcache.c > @@ -53,6 +53,8 @@ typedef struct MapCacheEntry { > uint8_t *vaddr_base; > unsigned long *valid_mapping; > uint8_t lock; > +#define XEN_MAPCACHE_ENTRY_DUMMY (1 << 0) > + uint8_t flags; > hwaddr size; > struct MapCacheEntry *next; > } MapCacheEntry; > @@ -150,7 +152,8 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, > void *opaque) > > static void xen_remap_bucket(MapCacheEntry *entry, > hwaddr size, > - hwaddr address_index) > + hwaddr address_index, > + bool dummy) > { > uint8_t *vaddr_base; > xen_pfn_t *pfns; > @@ -177,11 +180,27 @@ static void xen_remap_bucket(MapCacheEntry > *entry, > pfns[i] = (address_index << (MCACHE_BUCKET_SHIFT-XC_PAGE_SHIFT)) > + i; > } > > - vaddr_base = xenforeignmemory_map(xen_fmem, xen_domid, > PROT_READ|PROT_WRITE, > - nb_pfn, pfns, err); > - if (vaddr_base == NULL) { > - perror("xenforeignmemory_map"); > - exit(-1); > + if (!dummy) { > + vaddr_base = xenforeignmemory_map(xen_fmem, xen_domid, > + PROT_READ|PROT_WRITE, > + nb_pfn, pfns, err); > + if (vaddr_base == NULL) { > + perror("xenforeignmemory_map"); > + exit(-1); > + } > + entry->flags &= ~(XEN_MAPCACHE_ENTRY_DUMMY); > + } else { > + /* > + * 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, > + MAP_ANON|MAP_SHARED, -1, 0); > + if (vaddr_base == NULL) { > + perror("mmap"); > + exit(-1); > + } > + entry->flags |= XEN_MAPCACHE_ENTRY_DUMMY; > } > > entry->vaddr_base = vaddr_base; > @@ -211,6 +230,7 @@ static uint8_t *xen_map_cache_unlocked(hwaddr > phys_addr, hwaddr size, > hwaddr cache_size = size; > hwaddr test_bit_size; > bool translated = false; > + bool dummy = false; > > tryagain: > address_index = phys_addr >> MCACHE_BUCKET_SHIFT; > @@ -262,14 +282,14 @@ tryagain: > if (!entry) { > entry = g_malloc0(sizeof (MapCacheEntry)); > pentry->next = entry; > - xen_remap_bucket(entry, cache_size, address_index); > + xen_remap_bucket(entry, 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); > + xen_remap_bucket(entry, cache_size, address_index, dummy); > } > } > > @@ -282,6 +302,10 @@ tryagain: > translated = true; > goto tryagain; > } > + if (!dummy && runstate_check(RUN_STATE_INMIGRATE)) { > + dummy = true; > + goto tryagain; > + } > trace_xen_map_cache_return(NULL); > return NULL; > } > -- > 2.7.4
On Tue, 4 Jul 2017, Igor Druzhinin wrote: > Dummys are simple anonymous mappings that are placed instead > of regular foreign mappings in certain situations when we need > to postpone the actual mapping but still have to give a > memory region to QEMU to play with. > > This is planned to be used for restore on Xen. > > Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > hw/i386/xen/xen-mapcache.c | 40 ++++++++++++++++++++++++++++++++-------- > 1 file changed, 32 insertions(+), 8 deletions(-) > > diff --git a/hw/i386/xen/xen-mapcache.c b/hw/i386/xen/xen-mapcache.c > index e60156c..cd4e746 100644 > --- a/hw/i386/xen/xen-mapcache.c > +++ b/hw/i386/xen/xen-mapcache.c > @@ -53,6 +53,8 @@ typedef struct MapCacheEntry { > uint8_t *vaddr_base; > unsigned long *valid_mapping; > uint8_t lock; > +#define XEN_MAPCACHE_ENTRY_DUMMY (1 << 0) > + uint8_t flags; > hwaddr size; > struct MapCacheEntry *next; > } MapCacheEntry; > @@ -150,7 +152,8 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque) > > static void xen_remap_bucket(MapCacheEntry *entry, > hwaddr size, > - hwaddr address_index) > + hwaddr address_index, > + bool dummy) > { > uint8_t *vaddr_base; > xen_pfn_t *pfns; > @@ -177,11 +180,27 @@ static void xen_remap_bucket(MapCacheEntry *entry, > pfns[i] = (address_index << (MCACHE_BUCKET_SHIFT-XC_PAGE_SHIFT)) + i; > } > > - vaddr_base = xenforeignmemory_map(xen_fmem, xen_domid, PROT_READ|PROT_WRITE, > - nb_pfn, pfns, err); > - if (vaddr_base == NULL) { > - perror("xenforeignmemory_map"); > - exit(-1); > + if (!dummy) { > + vaddr_base = xenforeignmemory_map(xen_fmem, xen_domid, > + PROT_READ|PROT_WRITE, > + nb_pfn, pfns, err); > + if (vaddr_base == NULL) { > + perror("xenforeignmemory_map"); > + exit(-1); > + } > + entry->flags &= ~(XEN_MAPCACHE_ENTRY_DUMMY); > + } else { > + /* > + * 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, > + MAP_ANON|MAP_SHARED, -1, 0); > + if (vaddr_base == NULL) { > + perror("mmap"); > + exit(-1); > + } > + entry->flags |= XEN_MAPCACHE_ENTRY_DUMMY; > } > > entry->vaddr_base = vaddr_base; > @@ -211,6 +230,7 @@ static uint8_t *xen_map_cache_unlocked(hwaddr phys_addr, hwaddr size, > hwaddr cache_size = size; > hwaddr test_bit_size; > bool translated = false; > + bool dummy = false; > > tryagain: > address_index = phys_addr >> MCACHE_BUCKET_SHIFT; > @@ -262,14 +282,14 @@ tryagain: > if (!entry) { > entry = g_malloc0(sizeof (MapCacheEntry)); > pentry->next = entry; > - xen_remap_bucket(entry, cache_size, address_index); > + xen_remap_bucket(entry, 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); > + xen_remap_bucket(entry, cache_size, address_index, dummy); > } > } > > @@ -282,6 +302,10 @@ tryagain: > translated = true; > goto tryagain; > } > + if (!dummy && runstate_check(RUN_STATE_INMIGRATE)) { > + dummy = true; > + goto tryagain; > + } > trace_xen_map_cache_return(NULL); > return NULL; > } > -- > 2.7.4 >
diff --git a/hw/i386/xen/xen-mapcache.c b/hw/i386/xen/xen-mapcache.c index e60156c..cd4e746 100644 --- a/hw/i386/xen/xen-mapcache.c +++ b/hw/i386/xen/xen-mapcache.c @@ -53,6 +53,8 @@ typedef struct MapCacheEntry { uint8_t *vaddr_base; unsigned long *valid_mapping; uint8_t lock; +#define XEN_MAPCACHE_ENTRY_DUMMY (1 << 0) + uint8_t flags; hwaddr size; struct MapCacheEntry *next; } MapCacheEntry; @@ -150,7 +152,8 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void *opaque) static void xen_remap_bucket(MapCacheEntry *entry, hwaddr size, - hwaddr address_index) + hwaddr address_index, + bool dummy) { uint8_t *vaddr_base; xen_pfn_t *pfns; @@ -177,11 +180,27 @@ static void xen_remap_bucket(MapCacheEntry *entry, pfns[i] = (address_index << (MCACHE_BUCKET_SHIFT-XC_PAGE_SHIFT)) + i; } - vaddr_base = xenforeignmemory_map(xen_fmem, xen_domid, PROT_READ|PROT_WRITE, - nb_pfn, pfns, err); - if (vaddr_base == NULL) { - perror("xenforeignmemory_map"); - exit(-1); + if (!dummy) { + vaddr_base = xenforeignmemory_map(xen_fmem, xen_domid, + PROT_READ|PROT_WRITE, + nb_pfn, pfns, err); + if (vaddr_base == NULL) { + perror("xenforeignmemory_map"); + exit(-1); + } + entry->flags &= ~(XEN_MAPCACHE_ENTRY_DUMMY); + } else { + /* + * 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, + MAP_ANON|MAP_SHARED, -1, 0); + if (vaddr_base == NULL) { + perror("mmap"); + exit(-1); + } + entry->flags |= XEN_MAPCACHE_ENTRY_DUMMY; } entry->vaddr_base = vaddr_base; @@ -211,6 +230,7 @@ static uint8_t *xen_map_cache_unlocked(hwaddr phys_addr, hwaddr size, hwaddr cache_size = size; hwaddr test_bit_size; bool translated = false; + bool dummy = false; tryagain: address_index = phys_addr >> MCACHE_BUCKET_SHIFT; @@ -262,14 +282,14 @@ tryagain: if (!entry) { entry = g_malloc0(sizeof (MapCacheEntry)); pentry->next = entry; - xen_remap_bucket(entry, cache_size, address_index); + xen_remap_bucket(entry, 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); + xen_remap_bucket(entry, cache_size, address_index, dummy); } } @@ -282,6 +302,10 @@ tryagain: translated = true; goto tryagain; } + if (!dummy && runstate_check(RUN_STATE_INMIGRATE)) { + dummy = true; + goto tryagain; + } trace_xen_map_cache_return(NULL); return NULL; }
Dummys are simple anonymous mappings that are placed instead of regular foreign mappings in certain situations when we need to postpone the actual mapping but still have to give a memory region to QEMU to play with. This is planned to be used for restore on Xen. Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com> --- hw/i386/xen/xen-mapcache.c | 40 ++++++++++++++++++++++++++++++++-------- 1 file changed, 32 insertions(+), 8 deletions(-)