| Message ID | 20240227223501.28475-4-vikram.garhwal@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Xen: support grant mappings. | expand |
Vikram Garhwal <vikram.garhwal@amd.com> writes: > From: Juergen Gross <jgross@suse.com> > > qemu_map_ram_ptr() and qemu_ram_ptr_length() share quite some code, so > modify qemu_ram_ptr_length() a little bit and use it for > qemu_map_ram_ptr(), too. > > Signed-off-by: Juergen Gross <jgross@suse.com> > Signed-off-by: Vikram Garhwal <vikram.garhwal@amd.com> > Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > system/physmem.c | 56 ++++++++++++++++++++---------------------------- > 1 file changed, 23 insertions(+), 33 deletions(-) > <snip> > - > -/* Return a host pointer to guest's ram. Similar to qemu_map_ram_ptr > - * but takes a size argument. > +/* > + * Return a host pointer to guest's ram. > * > * Called within RCU critical section. > */ If you end up re-spinning it would be nice to kdoc this function and at least call out size as a return by ref and optional. > static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr, > hwaddr *size, bool lock) > { > - if (*size == 0) { > + hwaddr len = 0; > + > + if (size && *size == 0) { > return NULL; > } > > @@ -2207,7 +2181,10 @@ static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr, > block = qemu_get_ram_block(addr); > addr -= block->offset; > } > - *size = MIN(*size, block->max_length - addr); > + if (size) { > + *size = MIN(*size, block->max_length - addr); > + len = *size; > + } > > if (xen_enabled() && block->host == NULL) { > /* We need to check if the requested address is in the RAM > @@ -2215,7 +2192,7 @@ static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr, > * In that case just map the requested area. > */ > if (block->offset == 0) { > - return xen_map_cache(addr, *size, lock, lock); > + return xen_map_cache(addr, len, lock, lock); I did wonder if len == 0 will confuse things but it seems xen_map_cache will default to XC_PAGE_SIZE in that case. Anyway: Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
On Fri, Mar 01, 2024 at 05:04:54PM +0000, Alex Bennée wrote: > Vikram Garhwal <vikram.garhwal@amd.com> writes: > > > From: Juergen Gross <jgross@suse.com> > > > > qemu_map_ram_ptr() and qemu_ram_ptr_length() share quite some code, so > > modify qemu_ram_ptr_length() a little bit and use it for > > qemu_map_ram_ptr(), too. > > > > Signed-off-by: Juergen Gross <jgross@suse.com> > > Signed-off-by: Vikram Garhwal <vikram.garhwal@amd.com> > > Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > > --- > > system/physmem.c | 56 ++++++++++++++++++++---------------------------- > > 1 file changed, 23 insertions(+), 33 deletions(-) > > > <snip> > > - > > -/* Return a host pointer to guest's ram. Similar to qemu_map_ram_ptr > > - * but takes a size argument. > > +/* > > + * Return a host pointer to guest's ram. > > * > > * Called within RCU critical section. > > */ > > If you end up re-spinning it would be nice to kdoc this function and at > least call out size as a return by ref and optional. Will do if re-spinning is needed. > > > static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr, > > hwaddr *size, bool lock) > > { > > - if (*size == 0) { > > + hwaddr len = 0; > > + > > + if (size && *size == 0) { > > return NULL; > > } > > > > @@ -2207,7 +2181,10 @@ static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr, > > block = qemu_get_ram_block(addr); > > addr -= block->offset; > > } > > - *size = MIN(*size, block->max_length - addr); > > + if (size) { > > + *size = MIN(*size, block->max_length - addr); > > + len = *size; > > + } > > > > if (xen_enabled() && block->host == NULL) { > > /* We need to check if the requested address is in the RAM > > @@ -2215,7 +2192,7 @@ static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr, > > * In that case just map the requested area. > > */ > > if (block->offset == 0) { > > - return xen_map_cache(addr, *size, lock, lock); > > + return xen_map_cache(addr, len, lock, lock); > > I did wonder if len == 0 will confuse things but it seems xen_map_cache > will default to XC_PAGE_SIZE in that case. > > Anyway: > > Reviewed-by: Alex Bennée <alex.bennee@linaro.org> > > -- > Alex Bennée > Virtualisation Tech Lead @ Linaro
On Tue, Feb 27, 2024 at 11:37 PM Vikram Garhwal <vikram.garhwal@amd.com> wrote: > From: Juergen Gross <jgross@suse.com> > > qemu_map_ram_ptr() and qemu_ram_ptr_length() share quite some code, so > modify qemu_ram_ptr_length() a little bit and use it for > qemu_map_ram_ptr(), too. > > Signed-off-by: Juergen Gross <jgross@suse.com> > Signed-off-by: Vikram Garhwal <vikram.garhwal@amd.com> > Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com> > --- > system/physmem.c | 56 ++++++++++++++++++++---------------------------- > 1 file changed, 23 insertions(+), 33 deletions(-) > > diff --git a/system/physmem.c b/system/physmem.c > index 84f3022099..949dcb20ba 100644 > --- a/system/physmem.c > +++ b/system/physmem.c > @@ -2163,43 +2163,17 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t > length) > } > #endif /* !_WIN32 */ > > -/* Return a host pointer to ram allocated with qemu_ram_alloc. > - * This should not be used for general purpose DMA. Use address_space_map > - * or address_space_rw instead. For local memory (e.g. video ram) that the > - * device owns, use memory_region_get_ram_ptr. > - * > - * Called within RCU critical section. > - */ > -void *qemu_map_ram_ptr(RAMBlock *block, ram_addr_t addr) > -{ > - if (block == NULL) { > - block = qemu_get_ram_block(addr); > - addr -= block->offset; > - } > - > - if (xen_enabled() && block->host == NULL) { > - /* We need to check if the requested address is in the RAM > - * because we don't want to map the entire memory in QEMU. > - * In that case just map until the end of the page. > - */ > - if (block->offset == 0) { > - return xen_map_cache(addr, 0, 0, false); > - } > - > - block->host = xen_map_cache(block->offset, block->max_length, 1, > false); > - } > - return ramblock_ptr(block, addr); > -} > - > -/* Return a host pointer to guest's ram. Similar to qemu_map_ram_ptr > - * but takes a size argument. > +/* > + * Return a host pointer to guest's ram. > * > * Called within RCU critical section. > */ > static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr, > hwaddr *size, bool lock) > { > - if (*size == 0) { > + hwaddr len = 0; > + > + if (size && *size == 0) { > return NULL; > } > > @@ -2207,7 +2181,10 @@ static void *qemu_ram_ptr_length(RAMBlock *block, > ram_addr_t addr, > block = qemu_get_ram_block(addr); > addr -= block->offset; > } > - *size = MIN(*size, block->max_length - addr); > + if (size) { > + *size = MIN(*size, block->max_length - addr); > + len = *size; > + } > > if (xen_enabled() && block->host == NULL) { > /* We need to check if the requested address is in the RAM > @@ -2215,7 +2192,7 @@ static void *qemu_ram_ptr_length(RAMBlock *block, > ram_addr_t addr, > * In that case just map the requested area. > */ > if (block->offset == 0) { > - return xen_map_cache(addr, *size, lock, lock); > + return xen_map_cache(addr, len, lock, lock); > } > > block->host = xen_map_cache(block->offset, block->max_length, 1, > lock); > @@ -2224,6 +2201,19 @@ static void *qemu_ram_ptr_length(RAMBlock *block, > ram_addr_t addr, > return ramblock_ptr(block, addr); > } > > +/* > + * Return a host pointer to ram allocated with qemu_ram_alloc. > + * This should not be used for general purpose DMA. Use address_space_map > + * or address_space_rw instead. For local memory (e.g. video ram) that the > + * device owns, use memory_region_get_ram_ptr. > + * > + * Called within RCU critical section. > + */ > +void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr) > +{ > + return qemu_ram_ptr_length(ram_block, addr, NULL, false); > +} > + > /* Return the offset of a hostpointer within a ramblock */ > ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, void *host) > { > -- > 2.17.1 > > >
diff --git a/system/physmem.c b/system/physmem.c index 84f3022099..949dcb20ba 100644 --- a/system/physmem.c +++ b/system/physmem.c @@ -2163,43 +2163,17 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length) } #endif /* !_WIN32 */ -/* Return a host pointer to ram allocated with qemu_ram_alloc. - * This should not be used for general purpose DMA. Use address_space_map - * or address_space_rw instead. For local memory (e.g. video ram) that the - * device owns, use memory_region_get_ram_ptr. - * - * Called within RCU critical section. - */ -void *qemu_map_ram_ptr(RAMBlock *block, ram_addr_t addr) -{ - if (block == NULL) { - block = qemu_get_ram_block(addr); - addr -= block->offset; - } - - if (xen_enabled() && block->host == NULL) { - /* We need to check if the requested address is in the RAM - * because we don't want to map the entire memory in QEMU. - * In that case just map until the end of the page. - */ - if (block->offset == 0) { - return xen_map_cache(addr, 0, 0, false); - } - - block->host = xen_map_cache(block->offset, block->max_length, 1, false); - } - return ramblock_ptr(block, addr); -} - -/* Return a host pointer to guest's ram. Similar to qemu_map_ram_ptr - * but takes a size argument. +/* + * Return a host pointer to guest's ram. * * Called within RCU critical section. */ static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr, hwaddr *size, bool lock) { - if (*size == 0) { + hwaddr len = 0; + + if (size && *size == 0) { return NULL; } @@ -2207,7 +2181,10 @@ static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr, block = qemu_get_ram_block(addr); addr -= block->offset; } - *size = MIN(*size, block->max_length - addr); + if (size) { + *size = MIN(*size, block->max_length - addr); + len = *size; + } if (xen_enabled() && block->host == NULL) { /* We need to check if the requested address is in the RAM @@ -2215,7 +2192,7 @@ static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr, * In that case just map the requested area. */ if (block->offset == 0) { - return xen_map_cache(addr, *size, lock, lock); + return xen_map_cache(addr, len, lock, lock); } block->host = xen_map_cache(block->offset, block->max_length, 1, lock); @@ -2224,6 +2201,19 @@ static void *qemu_ram_ptr_length(RAMBlock *block, ram_addr_t addr, return ramblock_ptr(block, addr); } +/* + * Return a host pointer to ram allocated with qemu_ram_alloc. + * This should not be used for general purpose DMA. Use address_space_map + * or address_space_rw instead. For local memory (e.g. video ram) that the + * device owns, use memory_region_get_ram_ptr. + * + * Called within RCU critical section. + */ +void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr) +{ + return qemu_ram_ptr_length(ram_block, addr, NULL, false); +} + /* Return the offset of a hostpointer within a ramblock */ ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, void *host) {