Use qemu_real_host_page_size instead.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/mmap.c | 66 +++++++++++++++++++++++------------------------
1 file changed, 33 insertions(+), 33 deletions(-)
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 96c9433e27..4d3c8717b9 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -165,6 +165,7 @@ static int target_to_host_prot(int prot)
/* NOTE: all the constants are the HOST ones, but addresses are target. */
int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
{
+ int host_page_size = qemu_real_host_page_size();
abi_ulong starts[3];
abi_ulong lens[3];
int prots[3];
@@ -189,13 +190,13 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
}
last = start + len - 1;
- host_start = start & qemu_host_page_mask;
+ host_start = start & -host_page_size;
host_last = HOST_PAGE_ALIGN(last) - 1;
nranges = 0;
mmap_lock();
- if (host_last - host_start < qemu_host_page_size) {
+ if (host_last - host_start < host_page_size) {
/* Single host page contains all guest pages: sum the prot. */
prot1 = target_prot;
for (abi_ulong a = host_start; a < start; a += TARGET_PAGE_SIZE) {
@@ -205,7 +206,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
prot1 |= page_get_flags(a + 1);
}
starts[nranges] = host_start;
- lens[nranges] = qemu_host_page_size;
+ lens[nranges] = host_page_size;
prots[nranges] = prot1;
nranges++;
} else {
@@ -218,10 +219,10 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
/* If the resulting sum differs, create a new range. */
if (prot1 != target_prot) {
starts[nranges] = host_start;
- lens[nranges] = qemu_host_page_size;
+ lens[nranges] = host_page_size;
prots[nranges] = prot1;
nranges++;
- host_start += qemu_host_page_size;
+ host_start += host_page_size;
}
}
@@ -233,9 +234,9 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
}
/* If the resulting sum differs, create a new range. */
if (prot1 != target_prot) {
- host_last -= qemu_host_page_size;
+ host_last -= host_page_size;
starts[nranges] = host_last + 1;
- lens[nranges] = qemu_host_page_size;
+ lens[nranges] = host_page_size;
prots[nranges] = prot1;
nranges++;
}
@@ -270,6 +271,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
int prot, int flags, int fd, off_t offset)
{
+ int host_page_size = qemu_real_host_page_size();
abi_ulong real_last;
void *host_start;
int prot_old, prot_new;
@@ -286,7 +288,7 @@ static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
return false;
}
- real_last = real_start + qemu_host_page_size - 1;
+ real_last = real_start + host_page_size - 1;
host_start = g2h_untagged(real_start);
/* Get the protection of the target pages outside the mapping. */
@@ -304,12 +306,12 @@ static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
* outside of the fragment we need to map. Allocate a new host
* page to cover, discarding whatever else may have been present.
*/
- void *p = mmap(host_start, qemu_host_page_size,
+ void *p = mmap(host_start, host_page_size,
target_to_host_prot(prot),
flags | MAP_ANONYMOUS, -1, 0);
if (p != host_start) {
if (p != MAP_FAILED) {
- munmap(p, qemu_host_page_size);
+ munmap(p, host_page_size);
errno = EEXIST;
}
return false;
@@ -324,7 +326,7 @@ static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
/* Adjust protection to be able to write. */
if (!(host_prot_old & PROT_WRITE)) {
host_prot_old |= PROT_WRITE;
- mprotect(host_start, qemu_host_page_size, host_prot_old);
+ mprotect(host_start, host_page_size, host_prot_old);
}
/* Read or zero the new guest pages. */
@@ -338,7 +340,7 @@ static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
/* Put final protection */
if (host_prot_new != host_prot_old) {
- mprotect(host_start, qemu_host_page_size, host_prot_new);
+ mprotect(host_start, host_page_size, host_prot_new);
}
return true;
}
@@ -373,17 +375,18 @@ static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size,
*/
abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, abi_ulong align)
{
+ int host_page_size = qemu_real_host_page_size();
void *ptr, *prev;
abi_ulong addr;
int wrapped, repeat;
- align = MAX(align, qemu_host_page_size);
+ align = MAX(align, host_page_size);
/* If 'start' == 0, then a default start address is used. */
if (start == 0) {
start = mmap_next_start;
} else {
- start &= qemu_host_page_mask;
+ start &= -host_page_size;
}
start = ROUND_UP(start, align);
@@ -492,6 +495,7 @@ abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, abi_ulong align)
abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
int flags, int fd, off_t offset)
{
+ int host_page_size = qemu_real_host_page_size();
abi_ulong ret, last, real_start, real_last, retaddr, host_len;
abi_ulong passthrough_start = -1, passthrough_last = 0;
int page_flags;
@@ -537,8 +541,8 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
}
}
- real_start = start & qemu_host_page_mask;
- host_offset = offset & qemu_host_page_mask;
+ real_start = start & -host_page_size;
+ host_offset = offset & -host_page_size;
/*
* If the user is asking for the kernel to find a location, do that
@@ -567,8 +571,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
* may need to truncate file maps at EOF and add extra anonymous pages
* up to the targets page boundary.
*/
- if ((qemu_real_host_page_size() < qemu_host_page_size) &&
- !(flags & MAP_ANONYMOUS)) {
+ if (host_page_size < TARGET_PAGE_SIZE && !(flags & MAP_ANONYMOUS)) {
struct stat sb;
if (fstat(fd, &sb) == -1) {
@@ -595,11 +598,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
host_len = HOST_PAGE_ALIGN(host_len);
host_prot = target_to_host_prot(target_prot);
- /*
- * Note: we prefer to control the mapping address. It is
- * especially important if qemu_host_page_size >
- * qemu_real_host_page_size.
- */
+ /* Note: we prefer to control the mapping address. */
p = mmap(g2h_untagged(start), host_len, host_prot,
flags | MAP_FIXED | MAP_ANONYMOUS, -1, 0);
if (p == MAP_FAILED) {
@@ -665,7 +664,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
* aligned, so we read it
*/
if (!(flags & MAP_ANONYMOUS) &&
- (offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) {
+ (offset & (host_page_size - 1)) != (start & (host_page_size - 1))) {
/*
* msync() won't work here, so we return an error if write is
* possible while it is a shared mapping
@@ -694,7 +693,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
/* handle the start of the mapping */
if (start > real_start) {
- if (real_last == real_start + qemu_host_page_size - 1) {
+ if (real_last == real_start + host_page_size - 1) {
/* one single host page */
if (!mmap_frag(real_start, start, last,
target_prot, flags, fd, offset)) {
@@ -703,21 +702,21 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
goto the_end1;
}
if (!mmap_frag(real_start, start,
- real_start + qemu_host_page_size - 1,
+ real_start + host_page_size - 1,
target_prot, flags, fd, offset)) {
goto fail;
}
- real_start += qemu_host_page_size;
+ real_start += host_page_size;
}
/* handle the end of the mapping */
if (last < real_last) {
- abi_ulong real_page = real_last - qemu_host_page_size + 1;
+ abi_ulong real_page = real_last - host_page_size + 1;
if (!mmap_frag(real_page, real_page, last,
target_prot, flags, fd,
offset + real_page - start)) {
goto fail;
}
- real_last -= qemu_host_page_size;
+ real_last -= host_page_size;
}
/* map the middle (easier) */
@@ -784,6 +783,7 @@ fail:
static int mmap_reserve_or_unmap(abi_ulong start, abi_ulong len)
{
+ int host_page_size = qemu_real_host_page_size();
abi_ulong real_start;
abi_ulong real_last;
abi_ulong real_len;
@@ -793,7 +793,7 @@ static int mmap_reserve_or_unmap(abi_ulong start, abi_ulong len)
int prot;
last = start + len - 1;
- real_start = start & qemu_host_page_mask;
+ real_start = start & -host_page_size;
real_last = HOST_PAGE_ALIGN(last) - 1;
/*
@@ -802,7 +802,7 @@ static int mmap_reserve_or_unmap(abi_ulong start, abi_ulong len)
* The single page special case is required for the last page,
* lest real_start overflow to zero.
*/
- if (real_last - real_start < qemu_host_page_size) {
+ if (real_last - real_start < host_page_size) {
prot = 0;
for (a = real_start; a < start; a += TARGET_PAGE_SIZE) {
prot |= page_get_flags(a);
@@ -818,14 +818,14 @@ static int mmap_reserve_or_unmap(abi_ulong start, abi_ulong len)
prot |= page_get_flags(a);
}
if (prot != 0) {
- real_start += qemu_host_page_size;
+ real_start += host_page_size;
}
for (prot = 0, a = last; a < real_last; a += TARGET_PAGE_SIZE) {
prot |= page_get_flags(a + 1);
}
if (prot != 0) {
- real_last -= qemu_host_page_size;
+ real_last -= host_page_size;
}
if (real_last < real_start) {
--
2.34.1On Tue, Jan 02, 2024 at 12:57:43PM +1100, Richard Henderson wrote: > Use qemu_real_host_page_size instead. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > linux-user/mmap.c | 66 +++++++++++++++++++++++------------------------ > 1 file changed, 33 insertions(+), 33 deletions(-) Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
On 1/2/24 05:57, Richard Henderson wrote:
> Use qemu_real_host_page_size instead.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> linux-user/mmap.c | 66 +++++++++++++++++++++++------------------------
> 1 file changed, 33 insertions(+), 33 deletions(-)
>
> diff --git a/linux-user/mmap.c b/linux-user/mmap.c
> index 96c9433e27..4d3c8717b9 100644
> --- a/linux-user/mmap.c
> +++ b/linux-user/mmap.c
> @@ -165,6 +165,7 @@ static int target_to_host_prot(int prot)
> /* NOTE: all the constants are the HOST ones, but addresses are target. */
> int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
> {
> + int host_page_size = qemu_real_host_page_size();
> abi_ulong starts[3];
> abi_ulong lens[3];
> int prots[3];
> @@ -189,13 +190,13 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
> }
>
> last = start + len - 1;
> - host_start = start & qemu_host_page_mask;
> + host_start = start & -host_page_size;
> host_last = HOST_PAGE_ALIGN(last) - 1;
> nranges = 0;
>
> mmap_lock();
>
> - if (host_last - host_start < qemu_host_page_size) {
> + if (host_last - host_start < host_page_size) {
> /* Single host page contains all guest pages: sum the prot. */
> prot1 = target_prot;
> for (abi_ulong a = host_start; a < start; a += TARGET_PAGE_SIZE) {
> @@ -205,7 +206,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
> prot1 |= page_get_flags(a + 1);
> }
> starts[nranges] = host_start;
> - lens[nranges] = qemu_host_page_size;
> + lens[nranges] = host_page_size;
> prots[nranges] = prot1;
> nranges++;
> } else {
> @@ -218,10 +219,10 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
> /* If the resulting sum differs, create a new range. */
> if (prot1 != target_prot) {
> starts[nranges] = host_start;
> - lens[nranges] = qemu_host_page_size;
> + lens[nranges] = host_page_size;
> prots[nranges] = prot1;
> nranges++;
> - host_start += qemu_host_page_size;
> + host_start += host_page_size;
> }
> }
>
> @@ -233,9 +234,9 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
> }
> /* If the resulting sum differs, create a new range. */
> if (prot1 != target_prot) {
> - host_last -= qemu_host_page_size;
> + host_last -= host_page_size;
> starts[nranges] = host_last + 1;
> - lens[nranges] = qemu_host_page_size;
> + lens[nranges] = host_page_size;
> prots[nranges] = prot1;
> nranges++;
> }
> @@ -270,6 +271,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
> static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
> int prot, int flags, int fd, off_t offset)
> {
> + int host_page_size = qemu_real_host_page_size();
> abi_ulong real_last;
> void *host_start;
> int prot_old, prot_new;
> @@ -286,7 +288,7 @@ static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
> return false;
> }
>
> - real_last = real_start + qemu_host_page_size - 1;
> + real_last = real_start + host_page_size - 1;
> host_start = g2h_untagged(real_start);
>
> /* Get the protection of the target pages outside the mapping. */
> @@ -304,12 +306,12 @@ static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
> * outside of the fragment we need to map. Allocate a new host
> * page to cover, discarding whatever else may have been present.
> */
> - void *p = mmap(host_start, qemu_host_page_size,
> + void *p = mmap(host_start, host_page_size,
> target_to_host_prot(prot),
> flags | MAP_ANONYMOUS, -1, 0);
> if (p != host_start) {
> if (p != MAP_FAILED) {
> - munmap(p, qemu_host_page_size);
> + munmap(p, host_page_size);
> errno = EEXIST;
> }
> return false;
> @@ -324,7 +326,7 @@ static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
> /* Adjust protection to be able to write. */
> if (!(host_prot_old & PROT_WRITE)) {
> host_prot_old |= PROT_WRITE;
> - mprotect(host_start, qemu_host_page_size, host_prot_old);
> + mprotect(host_start, host_page_size, host_prot_old);
> }
>
> /* Read or zero the new guest pages. */
> @@ -338,7 +340,7 @@ static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
>
> /* Put final protection */
> if (host_prot_new != host_prot_old) {
> - mprotect(host_start, qemu_host_page_size, host_prot_new);
> + mprotect(host_start, host_page_size, host_prot_new);
> }
> return true;
> }
> @@ -373,17 +375,18 @@ static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size,
> */
> abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, abi_ulong align)
> {
> + int host_page_size = qemu_real_host_page_size();
> void *ptr, *prev;
> abi_ulong addr;
> int wrapped, repeat;
>
> - align = MAX(align, qemu_host_page_size);
> + align = MAX(align, host_page_size);
>
> /* If 'start' == 0, then a default start address is used. */
> if (start == 0) {
> start = mmap_next_start;
> } else {
> - start &= qemu_host_page_mask;
> + start &= -host_page_size;
> }
> start = ROUND_UP(start, align);
>
> @@ -492,6 +495,7 @@ abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, abi_ulong align)
> abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
> int flags, int fd, off_t offset)
> {
> + int host_page_size = qemu_real_host_page_size();
> abi_ulong ret, last, real_start, real_last, retaddr, host_len;
> abi_ulong passthrough_start = -1, passthrough_last = 0;
> int page_flags;
> @@ -537,8 +541,8 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
> }
> }
>
> - real_start = start & qemu_host_page_mask;
> - host_offset = offset & qemu_host_page_mask;
> + real_start = start & -host_page_size;
> + host_offset = offset & -host_page_size;
>
> /*
> * If the user is asking for the kernel to find a location, do that
> @@ -567,8 +571,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
> * may need to truncate file maps at EOF and add extra anonymous pages
> * up to the targets page boundary.
> */
> - if ((qemu_real_host_page_size() < qemu_host_page_size) &&
> - !(flags & MAP_ANONYMOUS)) {
> + if (host_page_size < TARGET_PAGE_SIZE && !(flags & MAP_ANONYMOUS)) {
> struct stat sb;
>
> if (fstat(fd, &sb) == -1) {
> @@ -595,11 +598,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
> host_len = HOST_PAGE_ALIGN(host_len);
> host_prot = target_to_host_prot(target_prot);
>
> - /*
> - * Note: we prefer to control the mapping address. It is
> - * especially important if qemu_host_page_size >
> - * qemu_real_host_page_size.
> - */
> + /* Note: we prefer to control the mapping address. */
> p = mmap(g2h_untagged(start), host_len, host_prot,
> flags | MAP_FIXED | MAP_ANONYMOUS, -1, 0);
> if (p == MAP_FAILED) {
> @@ -665,7 +664,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
> * aligned, so we read it
> */
> if (!(flags & MAP_ANONYMOUS) &&
> - (offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) {
> + (offset & (host_page_size - 1)) != (start & (host_page_size - 1))) {
> /*
> * msync() won't work here, so we return an error if write is
> * possible while it is a shared mapping
> @@ -694,7 +693,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
>
> /* handle the start of the mapping */
> if (start > real_start) {
> - if (real_last == real_start + qemu_host_page_size - 1) {
> + if (real_last == real_start + host_page_size - 1) {
> /* one single host page */
> if (!mmap_frag(real_start, start, last,
> target_prot, flags, fd, offset)) {
> @@ -703,21 +702,21 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
> goto the_end1;
> }
> if (!mmap_frag(real_start, start,
> - real_start + qemu_host_page_size - 1,
> + real_start + host_page_size - 1,
> target_prot, flags, fd, offset)) {
> goto fail;
> }
> - real_start += qemu_host_page_size;
> + real_start += host_page_size;
> }
> /* handle the end of the mapping */
> if (last < real_last) {
> - abi_ulong real_page = real_last - qemu_host_page_size + 1;
> + abi_ulong real_page = real_last - host_page_size + 1;
> if (!mmap_frag(real_page, real_page, last,
> target_prot, flags, fd,
> offset + real_page - start)) {
> goto fail;
> }
> - real_last -= qemu_host_page_size;
> + real_last -= host_page_size;
> }
>
> /* map the middle (easier) */
> @@ -784,6 +783,7 @@ fail:
>
> static int mmap_reserve_or_unmap(abi_ulong start, abi_ulong len)
> {
> + int host_page_size = qemu_real_host_page_size();
> abi_ulong real_start;
> abi_ulong real_last;
> abi_ulong real_len;
> @@ -793,7 +793,7 @@ static int mmap_reserve_or_unmap(abi_ulong start, abi_ulong len)
> int prot;
>
> last = start + len - 1;
> - real_start = start & qemu_host_page_mask;
> + real_start = start & -host_page_size;
> real_last = HOST_PAGE_ALIGN(last) - 1;
>
> /*
> @@ -802,7 +802,7 @@ static int mmap_reserve_or_unmap(abi_ulong start, abi_ulong len)
> * The single page special case is required for the last page,
> * lest real_start overflow to zero.
> */
> - if (real_last - real_start < qemu_host_page_size) {
> + if (real_last - real_start < host_page_size) {
> prot = 0;
> for (a = real_start; a < start; a += TARGET_PAGE_SIZE) {
> prot |= page_get_flags(a);
> @@ -818,14 +818,14 @@ static int mmap_reserve_or_unmap(abi_ulong start, abi_ulong len)
> prot |= page_get_flags(a);
> }
> if (prot != 0) {
> - real_start += qemu_host_page_size;
> + real_start += host_page_size;
> }
>
> for (prot = 0, a = last; a < real_last; a += TARGET_PAGE_SIZE) {
> prot |= page_get_flags(a + 1);
> }
> if (prot != 0) {
> - real_last -= qemu_host_page_size;
> + real_last -= host_page_size;
> }
>
> if (real_last < real_start) {
For me, the transformation ~page_mask == page_size - 1 and page_mask ==
-page_size was not so intuitive, until I tried it on paper.
Could it be useful to have macros PAGE_BITS(page_size), and
PAGE_MASK(page_size) for this?. All would be defined from page_sz, so
there is no duplicated data, and it would avoid a subtle error when
forgetting an operator, while helping to read the code.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
On 8/1/24 10:47, Pierrick Bouvier wrote:
> On 1/2/24 05:57, Richard Henderson wrote:
>> Use qemu_real_host_page_size instead.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>> linux-user/mmap.c | 66 +++++++++++++++++++++++------------------------
>> 1 file changed, 33 insertions(+), 33 deletions(-)
>>
>> diff --git a/linux-user/mmap.c b/linux-user/mmap.c
>> index 96c9433e27..4d3c8717b9 100644
>> --- a/linux-user/mmap.c
>> +++ b/linux-user/mmap.c
>> @@ -165,6 +165,7 @@ static int target_to_host_prot(int prot)
>> /* NOTE: all the constants are the HOST ones, but addresses are
>> target. */
>> int target_mprotect(abi_ulong start, abi_ulong len, int target_prot)
>> {
>> + int host_page_size = qemu_real_host_page_size();
>> abi_ulong starts[3];
>> abi_ulong lens[3];
>> int prots[3];
>> @@ -189,13 +190,13 @@ int target_mprotect(abi_ulong start, abi_ulong
>> len, int target_prot)
>> }
>> last = start + len - 1;
>> - host_start = start & qemu_host_page_mask;
>> + host_start = start & -host_page_size;
>> host_last = HOST_PAGE_ALIGN(last) - 1;
>> nranges = 0;
>> mmap_lock();
>> - if (host_last - host_start < qemu_host_page_size) {
>> + if (host_last - host_start < host_page_size) {
>> /* Single host page contains all guest pages: sum the prot. */
>> prot1 = target_prot;
>> for (abi_ulong a = host_start; a < start; a +=
>> TARGET_PAGE_SIZE) {
>> @@ -205,7 +206,7 @@ int target_mprotect(abi_ulong start, abi_ulong
>> len, int target_prot)
>> prot1 |= page_get_flags(a + 1);
>> }
>> starts[nranges] = host_start;
>> - lens[nranges] = qemu_host_page_size;
>> + lens[nranges] = host_page_size;
>> prots[nranges] = prot1;
>> nranges++;
>> } else {
>> @@ -218,10 +219,10 @@ int target_mprotect(abi_ulong start, abi_ulong
>> len, int target_prot)
>> /* If the resulting sum differs, create a new range. */
>> if (prot1 != target_prot) {
>> starts[nranges] = host_start;
>> - lens[nranges] = qemu_host_page_size;
>> + lens[nranges] = host_page_size;
>> prots[nranges] = prot1;
>> nranges++;
>> - host_start += qemu_host_page_size;
>> + host_start += host_page_size;
>> }
>> }
>> @@ -233,9 +234,9 @@ int target_mprotect(abi_ulong start, abi_ulong
>> len, int target_prot)
>> }
>> /* If the resulting sum differs, create a new range. */
>> if (prot1 != target_prot) {
>> - host_last -= qemu_host_page_size;
>> + host_last -= host_page_size;
>> starts[nranges] = host_last + 1;
>> - lens[nranges] = qemu_host_page_size;
>> + lens[nranges] = host_page_size;
>> prots[nranges] = prot1;
>> nranges++;
>> }
>> @@ -270,6 +271,7 @@ int target_mprotect(abi_ulong start, abi_ulong
>> len, int target_prot)
>> static bool mmap_frag(abi_ulong real_start, abi_ulong start,
>> abi_ulong last,
>> int prot, int flags, int fd, off_t offset)
>> {
>> + int host_page_size = qemu_real_host_page_size();
>> abi_ulong real_last;
>> void *host_start;
>> int prot_old, prot_new;
>> @@ -286,7 +288,7 @@ static bool mmap_frag(abi_ulong real_start,
>> abi_ulong start, abi_ulong last,
>> return false;
>> }
>> - real_last = real_start + qemu_host_page_size - 1;
>> + real_last = real_start + host_page_size - 1;
>> host_start = g2h_untagged(real_start);
>> /* Get the protection of the target pages outside the mapping. */
>> @@ -304,12 +306,12 @@ static bool mmap_frag(abi_ulong real_start,
>> abi_ulong start, abi_ulong last,
>> * outside of the fragment we need to map. Allocate a new host
>> * page to cover, discarding whatever else may have been
>> present.
>> */
>> - void *p = mmap(host_start, qemu_host_page_size,
>> + void *p = mmap(host_start, host_page_size,
>> target_to_host_prot(prot),
>> flags | MAP_ANONYMOUS, -1, 0);
>> if (p != host_start) {
>> if (p != MAP_FAILED) {
>> - munmap(p, qemu_host_page_size);
>> + munmap(p, host_page_size);
>> errno = EEXIST;
>> }
>> return false;
>> @@ -324,7 +326,7 @@ static bool mmap_frag(abi_ulong real_start,
>> abi_ulong start, abi_ulong last,
>> /* Adjust protection to be able to write. */
>> if (!(host_prot_old & PROT_WRITE)) {
>> host_prot_old |= PROT_WRITE;
>> - mprotect(host_start, qemu_host_page_size, host_prot_old);
>> + mprotect(host_start, host_page_size, host_prot_old);
>> }
>> /* Read or zero the new guest pages. */
>> @@ -338,7 +340,7 @@ static bool mmap_frag(abi_ulong real_start,
>> abi_ulong start, abi_ulong last,
>> /* Put final protection */
>> if (host_prot_new != host_prot_old) {
>> - mprotect(host_start, qemu_host_page_size, host_prot_new);
>> + mprotect(host_start, host_page_size, host_prot_new);
>> }
>> return true;
>> }
>> @@ -373,17 +375,18 @@ static abi_ulong
>> mmap_find_vma_reserved(abi_ulong start, abi_ulong size,
>> */
>> abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, abi_ulong
>> align)
>> {
>> + int host_page_size = qemu_real_host_page_size();
>> void *ptr, *prev;
>> abi_ulong addr;
>> int wrapped, repeat;
>> - align = MAX(align, qemu_host_page_size);
>> + align = MAX(align, host_page_size);
>> /* If 'start' == 0, then a default start address is used. */
>> if (start == 0) {
>> start = mmap_next_start;
>> } else {
>> - start &= qemu_host_page_mask;
>> + start &= -host_page_size;
>> }
>> start = ROUND_UP(start, align);
>> @@ -492,6 +495,7 @@ abi_ulong mmap_find_vma(abi_ulong start, abi_ulong
>> size, abi_ulong align)
>> abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
>> int flags, int fd, off_t offset)
>> {
>> + int host_page_size = qemu_real_host_page_size();
>> abi_ulong ret, last, real_start, real_last, retaddr, host_len;
>> abi_ulong passthrough_start = -1, passthrough_last = 0;
>> int page_flags;
>> @@ -537,8 +541,8 @@ abi_long target_mmap(abi_ulong start, abi_ulong
>> len, int target_prot,
>> }
>> }
>> - real_start = start & qemu_host_page_mask;
>> - host_offset = offset & qemu_host_page_mask;
>> + real_start = start & -host_page_size;
>> + host_offset = offset & -host_page_size;
>> /*
>> * If the user is asking for the kernel to find a location, do that
>> @@ -567,8 +571,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong
>> len, int target_prot,
>> * may need to truncate file maps at EOF and add extra anonymous
>> pages
>> * up to the targets page boundary.
>> */
>> - if ((qemu_real_host_page_size() < qemu_host_page_size) &&
>> - !(flags & MAP_ANONYMOUS)) {
>> + if (host_page_size < TARGET_PAGE_SIZE && !(flags & MAP_ANONYMOUS)) {
>> struct stat sb;
>> if (fstat(fd, &sb) == -1) {
>> @@ -595,11 +598,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong
>> len, int target_prot,
>> host_len = HOST_PAGE_ALIGN(host_len);
>> host_prot = target_to_host_prot(target_prot);
>> - /*
>> - * Note: we prefer to control the mapping address. It is
>> - * especially important if qemu_host_page_size >
>> - * qemu_real_host_page_size.
>> - */
>> + /* Note: we prefer to control the mapping address. */
>> p = mmap(g2h_untagged(start), host_len, host_prot,
>> flags | MAP_FIXED | MAP_ANONYMOUS, -1, 0);
>> if (p == MAP_FAILED) {
>> @@ -665,7 +664,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong
>> len, int target_prot,
>> * aligned, so we read it
>> */
>> if (!(flags & MAP_ANONYMOUS) &&
>> - (offset & ~qemu_host_page_mask) != (start &
>> ~qemu_host_page_mask)) {
>> + (offset & (host_page_size - 1)) != (start &
>> (host_page_size - 1))) {
>> /*
>> * msync() won't work here, so we return an error if
>> write is
>> * possible while it is a shared mapping
>> @@ -694,7 +693,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong
>> len, int target_prot,
>> /* handle the start of the mapping */
>> if (start > real_start) {
>> - if (real_last == real_start + qemu_host_page_size - 1) {
>> + if (real_last == real_start + host_page_size - 1) {
>> /* one single host page */
>> if (!mmap_frag(real_start, start, last,
>> target_prot, flags, fd, offset)) {
>> @@ -703,21 +702,21 @@ abi_long target_mmap(abi_ulong start, abi_ulong
>> len, int target_prot,
>> goto the_end1;
>> }
>> if (!mmap_frag(real_start, start,
>> - real_start + qemu_host_page_size - 1,
>> + real_start + host_page_size - 1,
>> target_prot, flags, fd, offset)) {
>> goto fail;
>> }
>> - real_start += qemu_host_page_size;
>> + real_start += host_page_size;
>> }
>> /* handle the end of the mapping */
>> if (last < real_last) {
>> - abi_ulong real_page = real_last - qemu_host_page_size + 1;
>> + abi_ulong real_page = real_last - host_page_size + 1;
>> if (!mmap_frag(real_page, real_page, last,
>> target_prot, flags, fd,
>> offset + real_page - start)) {
>> goto fail;
>> }
>> - real_last -= qemu_host_page_size;
>> + real_last -= host_page_size;
>> }
>> /* map the middle (easier) */
>> @@ -784,6 +783,7 @@ fail:
>> static int mmap_reserve_or_unmap(abi_ulong start, abi_ulong len)
>> {
>> + int host_page_size = qemu_real_host_page_size();
>> abi_ulong real_start;
>> abi_ulong real_last;
>> abi_ulong real_len;
>> @@ -793,7 +793,7 @@ static int mmap_reserve_or_unmap(abi_ulong start,
>> abi_ulong len)
>> int prot;
>> last = start + len - 1;
>> - real_start = start & qemu_host_page_mask;
>> + real_start = start & -host_page_size;
>> real_last = HOST_PAGE_ALIGN(last) - 1;
>> /*
>> @@ -802,7 +802,7 @@ static int mmap_reserve_or_unmap(abi_ulong start,
>> abi_ulong len)
>> * The single page special case is required for the last page,
>> * lest real_start overflow to zero.
>> */
>> - if (real_last - real_start < qemu_host_page_size) {
>> + if (real_last - real_start < host_page_size) {
>> prot = 0;
>> for (a = real_start; a < start; a += TARGET_PAGE_SIZE) {
>> prot |= page_get_flags(a);
>> @@ -818,14 +818,14 @@ static int mmap_reserve_or_unmap(abi_ulong
>> start, abi_ulong len)
>> prot |= page_get_flags(a);
>> }
>> if (prot != 0) {
>> - real_start += qemu_host_page_size;
>> + real_start += host_page_size;
>> }
>> for (prot = 0, a = last; a < real_last; a +=
>> TARGET_PAGE_SIZE) {
>> prot |= page_get_flags(a + 1);
>> }
>> if (prot != 0) {
>> - real_last -= qemu_host_page_size;
>> + real_last -= host_page_size;
>> }
>> if (real_last < real_start) {
>
> For me, the transformation ~page_mask == page_size - 1 and page_mask ==
> -page_size was not so intuitive, until I tried it on paper.
I have been there ;) Then when you have to deal with code related
to pages, this become natural page-related operations.
> Could it be useful to have macros PAGE_BITS(page_size), and
> PAGE_MASK(page_size) for this?. All would be defined from page_sz, so
> there is no duplicated data, and it would avoid a subtle error when
> forgetting an operator, while helping to read the code.
>
> Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
>
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