| Message ID | 20171212190212.5535-4-julien.grall@linaro.org |
|---|---|
| State | Accepted |
| Commit | b324c511906694ee27f7f06bfe99f343e8509f64 |
| Headers | show |
| Series | xen/arm: Stage-2 handling cleanup | expand |
On Tue, 12 Dec 2017, Julien Grall wrote: > The only differences between copy_to_guest (formerly called > raw_copy_to_guest_helper) and raw_copy_from_guest is: > - The direction of the memcpy > - The permission use for translating the address > > Extend copy_to_guest to support copying from guest VA by adding using a > bit in the flags to tell the direction of the copy. > > Lastly, reimplement raw_copy_from_guest using copy_to_guest. > > Signed-off-by: Julien Grall <julien.grall@linaro.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > Changes in v2: > - Use vaddr_t > --- > xen/arch/arm/guestcopy.c | 46 +++++++++++++--------------------------------- > 1 file changed, 13 insertions(+), 33 deletions(-) > > diff --git a/xen/arch/arm/guestcopy.c b/xen/arch/arm/guestcopy.c > index 08d0fa0a83..12fb03dd19 100644 > --- a/xen/arch/arm/guestcopy.c > +++ b/xen/arch/arm/guestcopy.c > @@ -6,6 +6,8 @@ > #include <asm/guest_access.h> > > #define COPY_flush_dcache (1U << 0) > +#define COPY_from_guest (0U << 1) > +#define COPY_to_guest (1U << 1) > > static unsigned long copy_guest(void *buf, uint64_t addr, unsigned int len, > unsigned int flags) > @@ -21,13 +23,18 @@ static unsigned long copy_guest(void *buf, uint64_t addr, unsigned int len, > unsigned size = min(len, (unsigned)PAGE_SIZE - offset); > struct page_info *page; > > - page = get_page_from_gva(current, addr, GV2M_WRITE); > + page = get_page_from_gva(current, addr, > + (flags & COPY_to_guest) ? GV2M_WRITE : GV2M_READ); > if ( page == NULL ) > return len; > > p = __map_domain_page(page); > p += offset; > - memcpy(p, buf, size); > + if ( flags & COPY_to_guest ) > + memcpy(p, buf, size); > + else > + memcpy(buf, p, size); > + > if ( flags & COPY_flush_dcache ) > clean_dcache_va_range(p, size); > > @@ -48,13 +55,14 @@ static unsigned long copy_guest(void *buf, uint64_t addr, unsigned int len, > > unsigned long raw_copy_to_guest(void *to, const void *from, unsigned len) > { > - return copy_guest((void *)from, (vaddr_t)to, len, 0); > + return copy_guest((void *)from, (vaddr_t)to, len, COPY_to_guest); > } > > unsigned long raw_copy_to_guest_flush_dcache(void *to, const void *from, > unsigned len) > { > - return copy_guest((void *)from, (vaddr_t)to, len, COPY_flush_dcache); > + return copy_guest((void *)from, (vaddr_t)to, len, > + COPY_to_guest | COPY_flush_dcache); > } > > unsigned long raw_clear_guest(void *to, unsigned len) > @@ -92,35 +100,7 @@ unsigned long raw_clear_guest(void *to, unsigned len) > > unsigned long raw_copy_from_guest(void *to, const void __user *from, unsigned len) > { > - unsigned offset = (vaddr_t)from & ~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) from, GV2M_READ); > - if ( page == NULL ) > - return len; > - > - p = __map_domain_page(page); > - p += ((vaddr_t)from & (~PAGE_MASK)); > - > - memcpy(to, p, size); > - > - unmap_domain_page(p); > - put_page(page); > - len -= size; > - from += size; > - to += size; > - /* > - * After the first iteration, guest virtual address is correctly > - * aligned to PAGE_SIZE. > - */ > - offset = 0; > - } > - return 0; > + return copy_guest(to, (vaddr_t)from, len, COPY_from_guest); > } > > /* > -- > 2.11.0 >
diff --git a/xen/arch/arm/guestcopy.c b/xen/arch/arm/guestcopy.c index 08d0fa0a83..12fb03dd19 100644 --- a/xen/arch/arm/guestcopy.c +++ b/xen/arch/arm/guestcopy.c @@ -6,6 +6,8 @@ #include <asm/guest_access.h> #define COPY_flush_dcache (1U << 0) +#define COPY_from_guest (0U << 1) +#define COPY_to_guest (1U << 1) static unsigned long copy_guest(void *buf, uint64_t addr, unsigned int len, unsigned int flags) @@ -21,13 +23,18 @@ static unsigned long copy_guest(void *buf, uint64_t addr, unsigned int len, unsigned size = min(len, (unsigned)PAGE_SIZE - offset); struct page_info *page; - page = get_page_from_gva(current, addr, GV2M_WRITE); + page = get_page_from_gva(current, addr, + (flags & COPY_to_guest) ? GV2M_WRITE : GV2M_READ); if ( page == NULL ) return len; p = __map_domain_page(page); p += offset; - memcpy(p, buf, size); + if ( flags & COPY_to_guest ) + memcpy(p, buf, size); + else + memcpy(buf, p, size); + if ( flags & COPY_flush_dcache ) clean_dcache_va_range(p, size); @@ -48,13 +55,14 @@ static unsigned long copy_guest(void *buf, uint64_t addr, unsigned int len, unsigned long raw_copy_to_guest(void *to, const void *from, unsigned len) { - return copy_guest((void *)from, (vaddr_t)to, len, 0); + return copy_guest((void *)from, (vaddr_t)to, len, COPY_to_guest); } unsigned long raw_copy_to_guest_flush_dcache(void *to, const void *from, unsigned len) { - return copy_guest((void *)from, (vaddr_t)to, len, COPY_flush_dcache); + return copy_guest((void *)from, (vaddr_t)to, len, + COPY_to_guest | COPY_flush_dcache); } unsigned long raw_clear_guest(void *to, unsigned len) @@ -92,35 +100,7 @@ unsigned long raw_clear_guest(void *to, unsigned len) unsigned long raw_copy_from_guest(void *to, const void __user *from, unsigned len) { - unsigned offset = (vaddr_t)from & ~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) from, GV2M_READ); - if ( page == NULL ) - return len; - - p = __map_domain_page(page); - p += ((vaddr_t)from & (~PAGE_MASK)); - - memcpy(to, p, size); - - unmap_domain_page(p); - put_page(page); - len -= size; - from += size; - to += size; - /* - * After the first iteration, guest virtual address is correctly - * aligned to PAGE_SIZE. - */ - offset = 0; - } - return 0; + return copy_guest(to, (vaddr_t)from, len, COPY_from_guest); } /*
The only differences between copy_to_guest (formerly called raw_copy_to_guest_helper) and raw_copy_from_guest is: - The direction of the memcpy - The permission use for translating the address Extend copy_to_guest to support copying from guest VA by adding using a bit in the flags to tell the direction of the copy. Lastly, reimplement raw_copy_from_guest using copy_to_guest. Signed-off-by: Julien Grall <julien.grall@linaro.org> --- Changes in v2: - Use vaddr_t --- xen/arch/arm/guestcopy.c | 46 +++++++++++++--------------------------------- 1 file changed, 13 insertions(+), 33 deletions(-)