Re: [Qemu-devel] [PATCH v4 18/29] vhost+postcopy: Resolve client address

[Dr. David Alan Gilbert]

* Marc-André Lureau (marcandre.lur...@gmail.com) wrote:
> Hi
> 
> On Thu, Mar 8, 2018 at 8:58 PM, Dr. David Alan Gilbert (git)
>  wrote:
> > From: "Dr. David Alan Gilbert" 
> >
> > Resolve fault addresses read off the clients UFD into RAMBlock
> > and offset, and call back to the postcopy code to ask for the page.
> >
> > Signed-off-by: Dr. David Alan Gilbert 
> > Reviewed-by: Peter Xu 
> 
> Reviewed-by: Marc-André Lureau 

Thanks,

> 
> > ---
> >  hw/virtio/trace-events |  3 +++
> >  hw/virtio/vhost-user.c | 31 ++-
> >  2 files changed, 33 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
> > index d7e9e1084b..3afd12cfea 100644
> > --- a/hw/virtio/trace-events
> > +++ b/hw/virtio/trace-events
> > @@ -7,6 +7,9 @@ vhost_region_add_section_abut(const char *name, uint64_t 
> > new_size) "%s: 0x%"PRIx
> >  vhost_section(const char *name, int r) "%s:%d"
> >
> >  # hw/virtio/vhost-user.c
> > +vhost_user_postcopy_fault_handler(const char *name, uint64_t 
> > fault_address, int nregions) "%s: @0x%"PRIx64" nregions:%d"
> > +vhost_user_postcopy_fault_handler_loop(int i, uint64_t client_base, 
> > uint64_t size) "%d: client 0x%"PRIx64" +0x%"PRIx64
> > +vhost_user_postcopy_fault_handler_found(int i, uint64_t region_offset, 
> > uint64_t rb_offset) "%d: region_offset: 0x%"PRIx64" rb_offset:0x%"PRIx64
> >  vhost_user_postcopy_listen(void) ""
> >  vhost_user_set_mem_table_postcopy(uint64_t client_addr, uint64_t qhva, int 
> > reply_i, int region_i) "client:0x%"PRIx64" for hva: 0x%"PRIx64" reply %d 
> > region %d"
> >  vhost_user_set_mem_table_withfd(int index, const char *name, uint64_t 
> > memory_size, uint64_t guest_phys_addr, uint64_t userspace_addr, uint64_t 
> > offset) "%d:%s: size:0x%"PRIx64" GPA:0x%"PRIx64" QVA/userspace:0x%"PRIx64" 
> > RB offset:0x%"PRIx64
> > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> > index fd65616961..e19b9ef9cf 100644
> > --- a/hw/virtio/vhost-user.c
> > +++ b/hw/virtio/vhost-user.c
> > @@ -26,6 +26,7 @@
> >  #include 
> >  #include 
> >  #include 
> > +#include 
> >
> >  #define VHOST_MEMORY_MAX_NREGIONS8
> >  #define VHOST_USER_F_PROTOCOL_FEATURES 30
> > @@ -974,7 +975,35 @@ out:
> >  static int vhost_user_postcopy_fault_handler(struct PostCopyFD *pcfd,
> >   void *ufd)
> >  {
> > -return 0;
> > +struct vhost_dev *dev = pcfd->data;
> > +struct vhost_user *u = dev->opaque;
> > +struct uffd_msg *msg = ufd;
> > +uint64_t faultaddr = msg->arg.pagefault.address;
> > +RAMBlock *rb = NULL;
> > +uint64_t rb_offset;
> > +int i;
> > +
> > +trace_vhost_user_postcopy_fault_handler(pcfd->idstr, faultaddr,
> > +dev->mem->nregions);
> > +for (i = 0; i < MIN(dev->mem->nregions, u->region_rb_len); i++) {
> > +trace_vhost_user_postcopy_fault_handler_loop(i,
> > +u->postcopy_client_bases[i], 
> > dev->mem->regions[i].memory_size);
> > +if (faultaddr >= u->postcopy_client_bases[i]) {
> > +/* Ofset of the fault address in the vhost region */
> > +uint64_t region_offset = faultaddr - 
> > u->postcopy_client_bases[i];
> > +if (region_offset < dev->mem->regions[i].memory_size) {
> > +rb_offset = region_offset + u->region_rb_offset[i];
> 
> It may be worth to add an assert (i < u->region_rb_len) ?

The loop limit guarantees that anyway with the 2nd term of the
MIN.

Dave

> 
> > +trace_vhost_user_postcopy_fault_handler_found(i,
> > +region_offset, rb_offset);
> > +rb = u->region_rb[i];
> > +return postcopy_request_shared_page(pcfd, rb, faultaddr,
> > +rb_offset);
> > +}
> > +}
> > +}
> > +error_report("%s: Failed to find region for fault %" PRIx64,
> > + __func__, faultaddr);
> > +return -1;
> >  }
> >
> >  /*
> > --
> > 2.14.3
> >
> >
> 
> 
> 
> -- 
> Marc-André Lureau
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH v4 18/29] vhost+postcopy: Resolve client address

[Marc-André Lureau]

Hi

On Thu, Mar 8, 2018 at 8:58 PM, Dr. David Alan Gilbert (git)
 wrote:
> From: "Dr. David Alan Gilbert" 
>
> Resolve fault addresses read off the clients UFD into RAMBlock
> and offset, and call back to the postcopy code to ask for the page.
>
> Signed-off-by: Dr. David Alan Gilbert 
> Reviewed-by: Peter Xu 

Reviewed-by: Marc-André Lureau 


> ---
>  hw/virtio/trace-events |  3 +++
>  hw/virtio/vhost-user.c | 31 ++-
>  2 files changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
> index d7e9e1084b..3afd12cfea 100644
> --- a/hw/virtio/trace-events
> +++ b/hw/virtio/trace-events
> @@ -7,6 +7,9 @@ vhost_region_add_section_abut(const char *name, uint64_t 
> new_size) "%s: 0x%"PRIx
>  vhost_section(const char *name, int r) "%s:%d"
>
>  # hw/virtio/vhost-user.c
> +vhost_user_postcopy_fault_handler(const char *name, uint64_t fault_address, 
> int nregions) "%s: @0x%"PRIx64" nregions:%d"
> +vhost_user_postcopy_fault_handler_loop(int i, uint64_t client_base, uint64_t 
> size) "%d: client 0x%"PRIx64" +0x%"PRIx64
> +vhost_user_postcopy_fault_handler_found(int i, uint64_t region_offset, 
> uint64_t rb_offset) "%d: region_offset: 0x%"PRIx64" rb_offset:0x%"PRIx64
>  vhost_user_postcopy_listen(void) ""
>  vhost_user_set_mem_table_postcopy(uint64_t client_addr, uint64_t qhva, int 
> reply_i, int region_i) "client:0x%"PRIx64" for hva: 0x%"PRIx64" reply %d 
> region %d"
>  vhost_user_set_mem_table_withfd(int index, const char *name, uint64_t 
> memory_size, uint64_t guest_phys_addr, uint64_t userspace_addr, uint64_t 
> offset) "%d:%s: size:0x%"PRIx64" GPA:0x%"PRIx64" QVA/userspace:0x%"PRIx64" RB 
> offset:0x%"PRIx64
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index fd65616961..e19b9ef9cf 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -26,6 +26,7 @@
>  #include 
>  #include 
>  #include 
> +#include 
>
>  #define VHOST_MEMORY_MAX_NREGIONS8
>  #define VHOST_USER_F_PROTOCOL_FEATURES 30
> @@ -974,7 +975,35 @@ out:
>  static int vhost_user_postcopy_fault_handler(struct PostCopyFD *pcfd,
>   void *ufd)
>  {
> -return 0;
> +struct vhost_dev *dev = pcfd->data;
> +struct vhost_user *u = dev->opaque;
> +struct uffd_msg *msg = ufd;
> +uint64_t faultaddr = msg->arg.pagefault.address;
> +RAMBlock *rb = NULL;
> +uint64_t rb_offset;
> +int i;
> +
> +trace_vhost_user_postcopy_fault_handler(pcfd->idstr, faultaddr,
> +dev->mem->nregions);
> +for (i = 0; i < MIN(dev->mem->nregions, u->region_rb_len); i++) {
> +trace_vhost_user_postcopy_fault_handler_loop(i,
> +u->postcopy_client_bases[i], 
> dev->mem->regions[i].memory_size);
> +if (faultaddr >= u->postcopy_client_bases[i]) {
> +/* Ofset of the fault address in the vhost region */
> +uint64_t region_offset = faultaddr - u->postcopy_client_bases[i];
> +if (region_offset < dev->mem->regions[i].memory_size) {
> +rb_offset = region_offset + u->region_rb_offset[i];

It may be worth to add an assert (i < u->region_rb_len) ?

> +trace_vhost_user_postcopy_fault_handler_found(i,
> +region_offset, rb_offset);
> +rb = u->region_rb[i];
> +return postcopy_request_shared_page(pcfd, rb, faultaddr,
> +rb_offset);
> +}
> +}
> +}
> +error_report("%s: Failed to find region for fault %" PRIx64,
> + __func__, faultaddr);
> +return -1;
>  }
>
>  /*
> --
> 2.14.3
>
>



-- 
Marc-André Lureau