| Message ID | 20171123183210.12045-5-julien.grall@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | xen/arm: Stage-2 handling cleanup | expand |
On Thu, 23 Nov 2017, Julien Grall wrote: > The function copy_to_guest can easily be extended to support zeroing > guest VA. To avoid using a new bit, it is considered that a NULL buffer > (i.e buf == NULL) means the guest memory will be zeroed. > > Lastly, reimplement raw_clear_guest using copy_to_guest. > > Signed-off-by: Julien Grall <julien.grall@linaro.org> Aside from the usual question about vaddr_t: Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > xen/arch/arm/guestcopy.c | 41 +++++++++++------------------------------ > 1 file changed, 11 insertions(+), 30 deletions(-) > > diff --git a/xen/arch/arm/guestcopy.c b/xen/arch/arm/guestcopy.c > index 1ffa717ca6..3aaa80859e 100644 > --- a/xen/arch/arm/guestcopy.c > +++ b/xen/arch/arm/guestcopy.c > @@ -29,7 +29,16 @@ static unsigned long copy_guest(void *buf, paddr_t addr, unsigned int len, > p = __map_domain_page(page); > p += offset; > if ( flags & COPY_to_guest ) > - memcpy(p, buf, size); > + { > + /* > + * buf will be NULL when the caller request to zero the > + * guest memory. > + */ > + if ( buf ) > + memcpy(p, buf, size); > + else > + memset(p, 0, size); > + } > else > memcpy(buf, p, size); > > @@ -65,35 +74,7 @@ unsigned long raw_copy_to_guest_flush_dcache(void *to, const void *from, > > unsigned long raw_clear_guest(void *to, unsigned len) > { > - /* XXX needs to handle faults */ > - unsigned offset = (vaddr_t)to & ~PAGE_MASK; > - > - while ( len ) > - { > - void *p; > - unsigned size = min(len, (unsigned)PAGE_SIZE - offset); > - struct page_info *page; > - > - page = get_page_from_gva(current, (vaddr_t) to, GV2M_WRITE); > - if ( page == NULL ) > - return len; > - > - p = __map_domain_page(page); > - p += offset; > - memset(p, 0x00, size); > - > - unmap_domain_page(p - offset); > - put_page(page); > - len -= size; > - to += size; > - /* > - * After the first iteration, guest virtual address is correctly > - * aligned to PAGE_SIZE. > - */ > - offset = 0; > - } > - > - return 0; > + return copy_guest(NULL, (unsigned long)to, len, COPY_to_guest); > } > > unsigned long raw_copy_from_guest(void *to, const void __user *from, unsigned len) > -- > 2.11.0 >
diff --git a/xen/arch/arm/guestcopy.c b/xen/arch/arm/guestcopy.c index 1ffa717ca6..3aaa80859e 100644 --- a/xen/arch/arm/guestcopy.c +++ b/xen/arch/arm/guestcopy.c @@ -29,7 +29,16 @@ static unsigned long copy_guest(void *buf, paddr_t addr, unsigned int len, p = __map_domain_page(page); p += offset; if ( flags & COPY_to_guest ) - memcpy(p, buf, size); + { + /* + * buf will be NULL when the caller request to zero the + * guest memory. + */ + if ( buf ) + memcpy(p, buf, size); + else + memset(p, 0, size); + } else memcpy(buf, p, size); @@ -65,35 +74,7 @@ unsigned long raw_copy_to_guest_flush_dcache(void *to, const void *from, unsigned long raw_clear_guest(void *to, unsigned len) { - /* XXX needs to handle faults */ - unsigned offset = (vaddr_t)to & ~PAGE_MASK; - - while ( len ) - { - void *p; - unsigned size = min(len, (unsigned)PAGE_SIZE - offset); - struct page_info *page; - - page = get_page_from_gva(current, (vaddr_t) to, GV2M_WRITE); - if ( page == NULL ) - return len; - - p = __map_domain_page(page); - p += offset; - memset(p, 0x00, size); - - unmap_domain_page(p - offset); - put_page(page); - len -= size; - to += size; - /* - * After the first iteration, guest virtual address is correctly - * aligned to PAGE_SIZE. - */ - offset = 0; - } - - return 0; + return copy_guest(NULL, (unsigned long)to, len, COPY_to_guest); } unsigned long raw_copy_from_guest(void *to, const void __user *from, unsigned len)
The function copy_to_guest can easily be extended to support zeroing guest VA. To avoid using a new bit, it is considered that a NULL buffer (i.e buf == NULL) means the guest memory will be zeroed. Lastly, reimplement raw_clear_guest using copy_to_guest. Signed-off-by: Julien Grall <julien.grall@linaro.org> --- xen/arch/arm/guestcopy.c | 41 +++++++++++------------------------------ 1 file changed, 11 insertions(+), 30 deletions(-)