From: "Dr. David Alan Gilbert" <dave@treblig.org>
Use the uffd_copy_page, uffd_zero_page and uffd_wakeup helpers
rather than calling ioctl ourselves.
They return -errno on error, and print an error_report themselves.
I think this actually makes postcopy_place_page actually more
consistent in it's callers.
Signed-off-by: Dr. David Alan Gilbert <dave@treblig.org>
---
migration/postcopy-ram.c | 47 +++++++++++-----------------------------
1 file changed, 13 insertions(+), 34 deletions(-)
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 1c374b7ea1..e2b318d3da 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -746,18 +746,9 @@ int postcopy_wake_shared(struct PostCopyFD *pcfd,
RAMBlock *rb)
{
size_t pagesize = qemu_ram_pagesize(rb);
- struct uffdio_range range;
- int ret;
trace_postcopy_wake_shared(client_addr, qemu_ram_get_idstr(rb));
- range.start = ROUND_DOWN(client_addr, pagesize);
- range.len = pagesize;
- ret = ioctl(pcfd->fd, UFFDIO_WAKE, &range);
- if (ret) {
- error_report("%s: Failed to wake: %zx in %s (%s)",
- __func__, (size_t)client_addr, qemu_ram_get_idstr(rb),
- strerror(errno));
- }
- return ret;
+ return uffd_wakeup(pcfd->fd, (void *)ROUND_DOWN(client_addr, pagesize),
+ pagesize);
}
static int postcopy_request_page(MigrationIncomingState *mis, RAMBlock *rb,
@@ -1275,18 +1266,10 @@ static int qemu_ufd_copy_ioctl(MigrationIncomingState *mis, void *host_addr,
int ret;
if (from_addr) {
- struct uffdio_copy copy_struct;
- copy_struct.dst = (uint64_t)(uintptr_t)host_addr;
- copy_struct.src = (uint64_t)(uintptr_t)from_addr;
- copy_struct.len = pagesize;
- copy_struct.mode = 0;
- ret = ioctl(userfault_fd, UFFDIO_COPY, ©_struct);
+ ret = uffd_copy_page(userfault_fd, host_addr, from_addr, pagesize,
+ false);
} else {
- struct uffdio_zeropage zero_struct;
- zero_struct.range.start = (uint64_t)(uintptr_t)host_addr;
- zero_struct.range.len = pagesize;
- zero_struct.mode = 0;
- ret = ioctl(userfault_fd, UFFDIO_ZEROPAGE, &zero_struct);
+ ret = uffd_zero_page(userfault_fd, host_addr, pagesize, false);
}
if (!ret) {
qemu_mutex_lock(&mis->page_request_mutex);
@@ -1343,18 +1326,16 @@ int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from,
RAMBlock *rb)
{
size_t pagesize = qemu_ram_pagesize(rb);
+ int e;
/* copy also acks to the kernel waking the stalled thread up
* TODO: We can inhibit that ack and only do it if it was requested
* which would be slightly cheaper, but we'd have to be careful
* of the order of updating our page state.
*/
- if (qemu_ufd_copy_ioctl(mis, host, from, pagesize, rb)) {
- int e = errno;
- error_report("%s: %s copy host: %p from: %p (size: %zd)",
- __func__, strerror(e), host, from, pagesize);
-
- return -e;
+ e = qemu_ufd_copy_ioctl(mis, host, from, pagesize, rb);
+ if (e) {
+ return e;
}
trace_postcopy_place_page(host);
@@ -1376,12 +1357,10 @@ int postcopy_place_page_zero(MigrationIncomingState *mis, void *host,
* but it's not available for everything (e.g. hugetlbpages)
*/
if (qemu_ram_is_uf_zeroable(rb)) {
- if (qemu_ufd_copy_ioctl(mis, host, NULL, pagesize, rb)) {
- int e = errno;
- error_report("%s: %s zero host: %p",
- __func__, strerror(e), host);
-
- return -e;
+ int e;
+ e = qemu_ufd_copy_ioctl(mis, host, NULL, pagesize, rb);
+ if (e) {
+ return e;
}
return postcopy_notify_shared_wake(rb,
qemu_ram_block_host_offset(rb,
--
2.46.1On Thu, Sep 19, 2024 at 02:46:25PM +0100, dave@treblig.org wrote:
> From: "Dr. David Alan Gilbert" <dave@treblig.org>
>
> Use the uffd_copy_page, uffd_zero_page and uffd_wakeup helpers
> rather than calling ioctl ourselves.
>
> They return -errno on error, and print an error_report themselves.
> I think this actually makes postcopy_place_page actually more
> consistent in it's callers.
>
> Signed-off-by: Dr. David Alan Gilbert <dave@treblig.org>
> ---
> migration/postcopy-ram.c | 47 +++++++++++-----------------------------
> 1 file changed, 13 insertions(+), 34 deletions(-)
>
> diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
> index 1c374b7ea1..e2b318d3da 100644
> --- a/migration/postcopy-ram.c
> +++ b/migration/postcopy-ram.c
> @@ -746,18 +746,9 @@ int postcopy_wake_shared(struct PostCopyFD *pcfd,
> RAMBlock *rb)
> {
> size_t pagesize = qemu_ram_pagesize(rb);
> - struct uffdio_range range;
> - int ret;
> trace_postcopy_wake_shared(client_addr, qemu_ram_get_idstr(rb));
> - range.start = ROUND_DOWN(client_addr, pagesize);
> - range.len = pagesize;
> - ret = ioctl(pcfd->fd, UFFDIO_WAKE, &range);
> - if (ret) {
> - error_report("%s: Failed to wake: %zx in %s (%s)",
> - __func__, (size_t)client_addr, qemu_ram_get_idstr(rb),
> - strerror(errno));
> - }
> - return ret;
> + return uffd_wakeup(pcfd->fd, (void *)ROUND_DOWN(client_addr, pagesize),
> + pagesize);
> }
There's a build issue on i386:
../migration/postcopy-ram.c: In function ‘postcopy_wake_shared’:
../migration/postcopy-ram.c:750:34: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
750 | return uffd_wakeup(pcfd->fd, (void *)ROUND_DOWN(client_addr, pagesize),
| ^
The plan is to squash below fix:
=========8<===========
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 03a63ef5cd..83f6160a36 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
-@@ -747,7 +747,8 @@ int postcopy_wake_shared(struct PostCopyFD *pcfd,
{
size_t pagesize = qemu_ram_pagesize(rb);
trace_postcopy_wake_shared(client_addr, qemu_ram_get_idstr(rb));
- return uffd_wakeup(pcfd->fd, (void *)ROUND_DOWN(client_addr, pagesize),
+ return uffd_wakeup(pcfd->fd,
+ (void *)(uintptr_t)ROUND_DOWN(client_addr, pagesize),
pagesize);
}
=========8<===========
Thanks,
--
Peter Xu
* Peter Xu (peterx@redhat.com) wrote:
> On Thu, Sep 19, 2024 at 02:46:25PM +0100, dave@treblig.org wrote:
> > From: "Dr. David Alan Gilbert" <dave@treblig.org>
> >
> > Use the uffd_copy_page, uffd_zero_page and uffd_wakeup helpers
> > rather than calling ioctl ourselves.
> >
> > They return -errno on error, and print an error_report themselves.
> > I think this actually makes postcopy_place_page actually more
> > consistent in it's callers.
> >
> > Signed-off-by: Dr. David Alan Gilbert <dave@treblig.org>
> > ---
> > migration/postcopy-ram.c | 47 +++++++++++-----------------------------
> > 1 file changed, 13 insertions(+), 34 deletions(-)
> >
> > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
> > index 1c374b7ea1..e2b318d3da 100644
> > --- a/migration/postcopy-ram.c
> > +++ b/migration/postcopy-ram.c
> > @@ -746,18 +746,9 @@ int postcopy_wake_shared(struct PostCopyFD *pcfd,
> > RAMBlock *rb)
> > {
> > size_t pagesize = qemu_ram_pagesize(rb);
> > - struct uffdio_range range;
> > - int ret;
> > trace_postcopy_wake_shared(client_addr, qemu_ram_get_idstr(rb));
> > - range.start = ROUND_DOWN(client_addr, pagesize);
> > - range.len = pagesize;
> > - ret = ioctl(pcfd->fd, UFFDIO_WAKE, &range);
> > - if (ret) {
> > - error_report("%s: Failed to wake: %zx in %s (%s)",
> > - __func__, (size_t)client_addr, qemu_ram_get_idstr(rb),
> > - strerror(errno));
> > - }
> > - return ret;
> > + return uffd_wakeup(pcfd->fd, (void *)ROUND_DOWN(client_addr, pagesize),
> > + pagesize);
> > }
>
> There's a build issue on i386:
>
> ../migration/postcopy-ram.c: In function ‘postcopy_wake_shared’:
> ../migration/postcopy-ram.c:750:34: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
> 750 | return uffd_wakeup(pcfd->fd, (void *)ROUND_DOWN(client_addr, pagesize),
> | ^
>
> The plan is to squash below fix:
Thanks!
Dave
> =========8<===========
> diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
> index 03a63ef5cd..83f6160a36 100644
> --- a/migration/postcopy-ram.c
> +++ b/migration/postcopy-ram.c
> -@@ -747,7 +747,8 @@ int postcopy_wake_shared(struct PostCopyFD *pcfd,
> {
> size_t pagesize = qemu_ram_pagesize(rb);
> trace_postcopy_wake_shared(client_addr, qemu_ram_get_idstr(rb));
> - return uffd_wakeup(pcfd->fd, (void *)ROUND_DOWN(client_addr, pagesize),
> + return uffd_wakeup(pcfd->fd,
> + (void *)(uintptr_t)ROUND_DOWN(client_addr, pagesize),
> pagesize);
> }
> =========8<===========
>
> Thanks,
>
> --
> Peter Xu
>
--
-----Open up your eyes, open up your mind, open up your code -------
/ Dr. David Alan Gilbert | Running GNU/Linux | Happy \
\ dave @ treblig.org | | In Hex /
\ _________________________|_____ http://www.treblig.org |_______/
On Thu, Sep 19, 2024 at 02:46:25PM +0100, dave@treblig.org wrote: > From: "Dr. David Alan Gilbert" <dave@treblig.org> > > Use the uffd_copy_page, uffd_zero_page and uffd_wakeup helpers > rather than calling ioctl ourselves. > > They return -errno on error, and print an error_report themselves. > I think this actually makes postcopy_place_page actually more > consistent in it's callers. > > Signed-off-by: Dr. David Alan Gilbert <dave@treblig.org> Reviewed-by: Peter Xu <peterx@redhat.com> -- Peter Xu
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