* Re: [PATCH v1 6/8]: PVH ballooning and grant changes
2012-09-21 19:19 [PATCH v1 6/8]: PVH ballooning and grant changes Mukesh Rathor
@ 2012-09-24 13:55 ` Stefano Stabellini
2012-09-26 1:22 ` Mukesh Rathor
2012-09-25 13:39 ` Ian Campbell
2012-10-02 10:52 ` Stefano Stabellini
2 siblings, 1 reply; 5+ messages in thread
From: Stefano Stabellini @ 2012-09-24 13:55 UTC (permalink / raw)
To: Mukesh Rathor
Cc: Xen-devel@lists.xensource.com, Ian Campbell, Stefano Stabellini,
Konrad Rzeszutek Wilk
On Fri, 21 Sep 2012, Mukesh Rathor wrote:
> ---
> drivers/xen/balloon.c | 35 ++++++++++++++++++++++++++++-------
> drivers/xen/gntdev.c | 3 ++-
> drivers/xen/grant-table.c | 25 +++++++++++++++++++++----
> 3 files changed, 51 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
> index 31ab82f..85a6917 100644
> --- a/drivers/xen/balloon.c
> +++ b/drivers/xen/balloon.c
> @@ -358,10 +358,21 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
> BUG_ON(!xen_feature(XENFEAT_auto_translated_physmap) &&
> phys_to_machine_mapping_valid(pfn));
>
> - set_phys_to_machine(pfn, frame_list[i]);
> + if (xen_pv_domain() &&
> + xen_feature(XENFEAT_auto_translated_physmap)) {
> + /* PVH: we just need to update native page table */
> + pte_t *ptep;
> + unsigned int level;
> + void *addr = __va(pfn << PAGE_SHIFT);
> + ptep = lookup_address((unsigned long)addr, &level);
> + set_pte(ptep, pfn_pte(pfn, PAGE_KERNEL));
> + } else
> + set_phys_to_machine(pfn, frame_list[i]);
> /* Link back into the page tables if not highmem. */
> - if (xen_pv_domain() && !PageHighMem(page)) {
> + if (xen_pv_domain() && !PageHighMem(page) &&
> + !xen_feature(XENFEAT_auto_translated_physmap)) {
> +
> int ret;
> ret = HYPERVISOR_update_va_mapping(
> (unsigned long)__va(pfn << PAGE_SHIFT),
> @@ -418,12 +429,21 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
> scrub_page(page);
>
> if (xen_pv_domain() && !PageHighMem(page)) {
> - ret = HYPERVISOR_update_va_mapping(
> - (unsigned long)__va(pfn << PAGE_SHIFT),
> - __pte_ma(0), 0);
> - BUG_ON(ret);
> + if (xen_feature(XENFEAT_auto_translated_physmap)) {
> + unsigned int level;
> + pte_t *ptep;
> + void *addr = __va(pfn << PAGE_SHIFT);
> + ptep = lookup_address((unsigned long)addr,
> + &level);
> + set_pte(ptep, __pte(0));
> +
> + } else {
> + ret = HYPERVISOR_update_va_mapping(
> + (unsigned long)__va(pfn << PAGE_SHIFT),
> + __pte_ma(0), 0);
> + BUG_ON(ret);
> + }
> }
> -
> }
>
> /* Ensure that ballooned highmem pages don't have kmaps. */
> @@ -433,6 +453,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
> /* No more mappings: invalidate P2M and add to balloon. */
> for (i = 0; i < nr_pages; i++) {
> pfn = mfn_to_pfn(frame_list[i]);
> + /* PVH note: following will noop for auto translated */
> __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
> balloon_append(pfn_to_page(pfn));
> }
Maybe we need a function "update_mapping" internal to balloon.c that
would be set to HYPERVISOR_update_va_mapping for pv guests, set_pte for
pvh guests and nothing for pv on hvm guests.
Speaking of which, why do pvh guests need a set_pte while pv on hvm
guests don't? I would think that their behaviour should be the same
regarding ballooning.
> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
> index 1ffd03b..35d1e3c 100644
> --- a/drivers/xen/gntdev.c
> +++ b/drivers/xen/gntdev.c
> @@ -802,7 +802,8 @@ static int __init gntdev_init(void)
> if (!xen_domain())
> return -ENODEV;
>
> - use_ptemod = xen_pv_domain();
> + use_ptemod = xen_pv_domain() &&
> + !xen_feature(XENFEAT_auto_translated_physmap);
>
> err = misc_register(&gntdev_miscdev);
> if (err != 0) {
> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> index 0bfc1ef..d831d52 100644
> --- a/drivers/xen/grant-table.c
> +++ b/drivers/xen/grant-table.c
> @@ -974,14 +974,19 @@ static void gnttab_unmap_frames_v2(void)
> static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
> {
> struct gnttab_setup_table setup;
> - unsigned long *frames;
> + unsigned long *frames, start_gpfn;
> unsigned int nr_gframes = end_idx + 1;
> int rc;
>
> - if (xen_hvm_domain()) {
> + if (xen_hvm_domain() || xen_feature(XENFEAT_auto_translated_physmap)) {
> struct xen_add_to_physmap xatp;
> unsigned int i = end_idx;
> rc = 0;
> +
> + if (xen_hvm_domain())
> + start_gpfn = xen_hvm_resume_frames >> PAGE_SHIFT;
> + else
> + start_gpfn = virt_to_pfn(gnttab_shared.addr);
> /*
> * Loop backwards, so that the first hypercall has the largest
> * index, ensuring that the table will grow only once.
> @@ -990,7 +995,7 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
> xatp.domid = DOMID_SELF;
> xatp.idx = i;
> xatp.space = XENMAPSPACE_grant_table;
> - xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i;
> + xatp.gpfn = start_gpfn + i;
> rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
> if (rc != 0) {
> printk(KERN_WARNING
> @@ -1053,7 +1058,7 @@ static void gnttab_request_version(void)
> int rc;
> struct gnttab_set_version gsv;
>
> - if (xen_hvm_domain())
> + if (xen_hvm_domain() || xen_feature(XENFEAT_auto_translated_physmap))
> gsv.version = 1;
> else
> gsv.version = 2;
> @@ -1081,12 +1086,24 @@ static void gnttab_request_version(void)
> int gnttab_resume(void)
> {
> unsigned int max_nr_gframes;
> + char *kmsg="Failed to kmalloc pages for pv in hvm grant frames\n";
>
> gnttab_request_version();
> max_nr_gframes = gnttab_max_grant_frames();
> if (max_nr_gframes < nr_grant_frames)
> return -ENOSYS;
>
> + /* PVH note: xen will free existing kmalloc'd mfn in
> + * XENMEM_add_to_physmap */
> + if (xen_pv_domain() && xen_feature(XENFEAT_auto_translated_physmap) &&
> + !gnttab_shared.addr) {
> + gnttab_shared.addr =
> + kmalloc(max_nr_gframes * PAGE_SIZE, GFP_KERNEL);
> + if ( !gnttab_shared.addr ) {
> + printk(KERN_WARNING "%s", kmsg);
> + return -ENOMEM;
> + }
> + }
the way PVH guests use gnttab_shared.addr is very similar to the way PV
on HVM guests use xen_hvm_resume_frames, except that
xen_hvm_resume_frames is allocated using alloc_xen_mmio instead of
kmalloc.
I wonder if it would produce better code switching PV on HVM guests to
gnttab_shared.addr too (or PVH guests to xen_hvm_resume_frames, but then
xen_hvm_resume_frames would need to be renamed).
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v1 6/8]: PVH ballooning and grant changes
2012-09-24 13:55 ` Stefano Stabellini
@ 2012-09-26 1:22 ` Mukesh Rathor
0 siblings, 0 replies; 5+ messages in thread
From: Mukesh Rathor @ 2012-09-26 1:22 UTC (permalink / raw)
To: Stefano Stabellini
Cc: Xen-devel@lists.xensource.com, Ian Campbell,
Konrad Rzeszutek Wilk
On Mon, 24 Sep 2012 14:55:06 +0100
Stefano Stabellini <stefano.stabellini@eu.citrix.com> wrote:
> On Fri, 21 Sep 2012, Mukesh Rathor wrote:
> > ---
> > drivers/xen/balloon.c | 35
> > ++++++++++++++++++++++++++++------- drivers/xen/gntdev.c |
> > 3 ++- drivers/xen/grant-table.c | 25 +++++++++++++++++++++----
> > 3 files changed, 51 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
> > index 31ab82f..85a6917 100644
> > --- a/drivers/xen/balloon.c
> > +++ b/drivers/xen/balloon.c
> > @@ -358,10 +358,21 @@ static enum bp_state
> > increase_reservation(unsigned long nr_pages)
> > BUG_ON(!xen_feature(XENFEAT_auto_translated_physmap) &&
> > phys_to_machine_mapping_valid(pfn));
> > - set_phys_to_machine(pfn, frame_list[i]);
> > + if (xen_pv_domain() &&
> > + xen_feature(XENFEAT_auto_translated_physmap)) {
> > + /* PVH: we just need to update native page
> > table */
> > + pte_t *ptep;
> > + unsigned int level;
> > + void *addr = __va(pfn << PAGE_SHIFT);
> > + ptep = lookup_address((unsigned long)addr,
> > &level);
> > + set_pte(ptep, pfn_pte(pfn, PAGE_KERNEL));
> > + } else
> > + set_phys_to_machine(pfn, frame_list[i]);
>
>
>
> > /* Link back into the page tables if not highmem.
> > */
> > - if (xen_pv_domain() && !PageHighMem(page)) {
> > + if (xen_pv_domain() && !PageHighMem(page) &&
> > + !xen_feature(XENFEAT_auto_translated_physmap))
> > { +
> > int ret;
> > ret = HYPERVISOR_update_va_mapping(
> > (unsigned long)__va(pfn <<
> > PAGE_SHIFT), @@ -418,12 +429,21 @@ static enum bp_state
> > decrease_reservation(unsigned long nr_pages, gfp_t gfp)
> > scrub_page(page);
> > if (xen_pv_domain() && !PageHighMem(page)) {
> > - ret = HYPERVISOR_update_va_mapping(
> > - (unsigned long)__va(pfn <<
> > PAGE_SHIFT),
> > - __pte_ma(0), 0);
> > - BUG_ON(ret);
> > + if
> > (xen_feature(XENFEAT_auto_translated_physmap)) {
> > + unsigned int level;
> > + pte_t *ptep;
> > + void *addr = __va(pfn <<
> > PAGE_SHIFT);
> > + ptep = lookup_address((unsigned
> > long)addr,
> > + &level);
> > + set_pte(ptep, __pte(0));
> > +
> > + } else {
> > + ret = HYPERVISOR_update_va_mapping(
> > + (unsigned long)__va(pfn <<
> > PAGE_SHIFT),
> > + __pte_ma(0), 0);
> > + BUG_ON(ret);
> > + }
> > }
> > -
> > }
> >
> > /* Ensure that ballooned highmem pages don't have kmaps. */
> > @@ -433,6 +453,7 @@ static enum bp_state
> > decrease_reservation(unsigned long nr_pages, gfp_t gfp) /* No more
> > mappings: invalidate P2M and add to balloon. */ for (i = 0; i <
> > nr_pages; i++) { pfn = mfn_to_pfn(frame_list[i]);
> > + /* PVH note: following will noop for auto
> > translated */ __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
> > balloon_append(pfn_to_page(pfn));
> > }
>
> Maybe we need a function "update_mapping" internal to balloon.c that
> would be set to HYPERVISOR_update_va_mapping for pv guests, set_pte
> for pvh guests and nothing for pv on hvm guests.
>
> Speaking of which, why do pvh guests need a set_pte while pv on hvm
> guests don't? I would think that their behaviour should be the same
> regarding ballooning.
you are right, I can remove it. Not sure why I've it there. Cant
recall.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v1 6/8]: PVH ballooning and grant changes
2012-09-21 19:19 [PATCH v1 6/8]: PVH ballooning and grant changes Mukesh Rathor
2012-09-24 13:55 ` Stefano Stabellini
@ 2012-09-25 13:39 ` Ian Campbell
2012-10-02 10:52 ` Stefano Stabellini
2 siblings, 0 replies; 5+ messages in thread
From: Ian Campbell @ 2012-09-25 13:39 UTC (permalink / raw)
To: Mukesh Rathor
Cc: Xen-devel@lists.xensource.com, Stefano Stabellini,
Konrad Rzeszutek Wilk
On Fri, 2012-09-21 at 20:19 +0100, Mukesh Rathor wrote:
> ---
> drivers/xen/balloon.c | 35 ++++++++++++++++++++++++++++-------
> drivers/xen/gntdev.c | 3 ++-
> drivers/xen/grant-table.c | 25 +++++++++++++++++++++----
> 3 files changed, 51 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
> index 31ab82f..85a6917 100644
> --- a/drivers/xen/balloon.c
> +++ b/drivers/xen/balloon.c
> @@ -358,10 +358,21 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
> BUG_ON(!xen_feature(XENFEAT_auto_translated_physmap) &&
> phys_to_machine_mapping_valid(pfn));
>
> - set_phys_to_machine(pfn, frame_list[i]);
> + if (xen_pv_domain() &&
> + xen_feature(XENFEAT_auto_translated_physmap)) {
> + /* PVH: we just need to update native page table */
Do you not need a PageHighMem check here somewhere? (although this is
moot if you follow the suggestion below)
> + pte_t *ptep;
> + unsigned int level;
> + void *addr = __va(pfn << PAGE_SHIFT);
> + ptep = lookup_address((unsigned long)addr, &level);
> + set_pte(ptep, pfn_pte(pfn, PAGE_KERNEL));
> + } else
> + set_phys_to_machine(pfn, frame_list[i]);
>
> /* Link back into the page tables if not highmem. */
> - if (xen_pv_domain() && !PageHighMem(page)) {
> + if (xen_pv_domain() && !PageHighMem(page) &&
> + !xen_feature(XENFEAT_auto_translated_physmap)) {
I think it would be more logical to put the PVH PT update here next to
the PV PT update and gate the set_phys_to_machine above on !a_t_pm, like
how you've done it in the decrease case.
(or perhaps per your comment below set_phys_to_machine isa NOP also on
PVH?)
> +
> int ret;
> ret = HYPERVISOR_update_va_mapping(
> (unsigned long)__va(pfn << PAGE_SHIFT),
> @@ -418,12 +429,21 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
> scrub_page(page);
>
> if (xen_pv_domain() && !PageHighMem(page)) {
> - ret = HYPERVISOR_update_va_mapping(
> - (unsigned long)__va(pfn << PAGE_SHIFT),
> - __pte_ma(0), 0);
> - BUG_ON(ret);
> + if (xen_feature(XENFEAT_auto_translated_physmap)) {
> + unsigned int level;
> + pte_t *ptep;
> + void *addr = __va(pfn << PAGE_SHIFT);
> + ptep = lookup_address((unsigned long)addr,
> + &level);
> + set_pte(ptep, __pte(0));
> +
> + } else {
> + ret = HYPERVISOR_update_va_mapping(
> + (unsigned long)__va(pfn << PAGE_SHIFT),
> + __pte_ma(0), 0);
> + BUG_ON(ret);
> + }
> }
> -
> }
>
> /* Ensure that ballooned highmem pages don't have kmaps. */
> @@ -433,6 +453,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
> /* No more mappings: invalidate P2M and add to balloon. */
> for (i = 0; i < nr_pages; i++) {
> pfn = mfn_to_pfn(frame_list[i]);
> + /* PVH note: following will noop for auto translated */
> __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
> balloon_append(pfn_to_page(pfn));
> }
> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
> index 1ffd03b..35d1e3c 100644
> --- a/drivers/xen/gntdev.c
> +++ b/drivers/xen/gntdev.c
> @@ -802,7 +802,8 @@ static int __init gntdev_init(void)
> if (!xen_domain())
> return -ENODEV;
>
> - use_ptemod = xen_pv_domain();
> + use_ptemod = xen_pv_domain() &&
> + !xen_feature(XENFEAT_auto_translated_physmap);
I keep wondering if
#define XENFEAT(x) xen_feature(XENFEAT_#x)
might not be useful to keep some of these long lines under control.
Probably not, since the bulk is the "x" bit...
Ian.
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v1 6/8]: PVH ballooning and grant changes
2012-09-21 19:19 [PATCH v1 6/8]: PVH ballooning and grant changes Mukesh Rathor
2012-09-24 13:55 ` Stefano Stabellini
2012-09-25 13:39 ` Ian Campbell
@ 2012-10-02 10:52 ` Stefano Stabellini
2 siblings, 0 replies; 5+ messages in thread
From: Stefano Stabellini @ 2012-10-02 10:52 UTC (permalink / raw)
To: Mukesh Rathor
Cc: Xen-devel@lists.xensource.com, Ian Campbell, Stefano Stabellini,
Konrad Rzeszutek Wilk
On Fri, 21 Sep 2012, Mukesh Rathor wrote:
>
> ---
> drivers/xen/balloon.c | 35 ++++++++++++++++++++++++++++-------
> drivers/xen/gntdev.c | 3 ++-
> drivers/xen/grant-table.c | 25 +++++++++++++++++++++----
> 3 files changed, 51 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
> index 31ab82f..85a6917 100644
> --- a/drivers/xen/balloon.c
> +++ b/drivers/xen/balloon.c
> @@ -358,10 +358,21 @@ static enum bp_state increase_reservation(unsigned long nr_pages)
> BUG_ON(!xen_feature(XENFEAT_auto_translated_physmap) &&
> phys_to_machine_mapping_valid(pfn));
>
> - set_phys_to_machine(pfn, frame_list[i]);
> + if (xen_pv_domain() &&
> + xen_feature(XENFEAT_auto_translated_physmap)) {
> + /* PVH: we just need to update native page table */
> + pte_t *ptep;
> + unsigned int level;
> + void *addr = __va(pfn << PAGE_SHIFT);
> + ptep = lookup_address((unsigned long)addr, &level);
> + set_pte(ptep, pfn_pte(pfn, PAGE_KERNEL));
> + } else
> + set_phys_to_machine(pfn, frame_list[i]);
>
> /* Link back into the page tables if not highmem. */
> - if (xen_pv_domain() && !PageHighMem(page)) {
> + if (xen_pv_domain() && !PageHighMem(page) &&
> + !xen_feature(XENFEAT_auto_translated_physmap)) {
> +
> int ret;
> ret = HYPERVISOR_update_va_mapping(
> (unsigned long)__va(pfn << PAGE_SHIFT),
> @@ -418,12 +429,21 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
> scrub_page(page);
>
> if (xen_pv_domain() && !PageHighMem(page)) {
> - ret = HYPERVISOR_update_va_mapping(
> - (unsigned long)__va(pfn << PAGE_SHIFT),
> - __pte_ma(0), 0);
> - BUG_ON(ret);
> + if (xen_feature(XENFEAT_auto_translated_physmap)) {
> + unsigned int level;
> + pte_t *ptep;
> + void *addr = __va(pfn << PAGE_SHIFT);
> + ptep = lookup_address((unsigned long)addr,
> + &level);
> + set_pte(ptep, __pte(0));
> +
> + } else {
> + ret = HYPERVISOR_update_va_mapping(
> + (unsigned long)__va(pfn << PAGE_SHIFT),
> + __pte_ma(0), 0);
> + BUG_ON(ret);
> + }
> }
> -
> }
>
> /* Ensure that ballooned highmem pages don't have kmaps. */
> @@ -433,6 +453,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp)
> /* No more mappings: invalidate P2M and add to balloon. */
> for (i = 0; i < nr_pages; i++) {
> pfn = mfn_to_pfn(frame_list[i]);
> + /* PVH note: following will noop for auto translated */
> __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
> balloon_append(pfn_to_page(pfn));
> }
> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
> index 1ffd03b..35d1e3c 100644
> --- a/drivers/xen/gntdev.c
> +++ b/drivers/xen/gntdev.c
> @@ -802,7 +802,8 @@ static int __init gntdev_init(void)
> if (!xen_domain())
> return -ENODEV;
>
> - use_ptemod = xen_pv_domain();
> + use_ptemod = xen_pv_domain() &&
> + !xen_feature(XENFEAT_auto_translated_physmap);
>
> err = misc_register(&gntdev_miscdev);
> if (err != 0) {
> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> index 0bfc1ef..d831d52 100644
> --- a/drivers/xen/grant-table.c
> +++ b/drivers/xen/grant-table.c
> @@ -974,14 +974,19 @@ static void gnttab_unmap_frames_v2(void)
> static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
> {
> struct gnttab_setup_table setup;
> - unsigned long *frames;
> + unsigned long *frames, start_gpfn;
> unsigned int nr_gframes = end_idx + 1;
> int rc;
>
> - if (xen_hvm_domain()) {
> + if (xen_hvm_domain() || xen_feature(XENFEAT_auto_translated_physmap)) {
> struct xen_add_to_physmap xatp;
> unsigned int i = end_idx;
> rc = 0;
> +
> + if (xen_hvm_domain())
> + start_gpfn = xen_hvm_resume_frames >> PAGE_SHIFT;
> + else
> + start_gpfn = virt_to_pfn(gnttab_shared.addr);
> /*
> * Loop backwards, so that the first hypercall has the largest
> * index, ensuring that the table will grow only once.
> @@ -990,7 +995,7 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
> xatp.domid = DOMID_SELF;
> xatp.idx = i;
> xatp.space = XENMAPSPACE_grant_table;
> - xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i;
> + xatp.gpfn = start_gpfn + i;
> rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
> if (rc != 0) {
> printk(KERN_WARNING
> @@ -1053,7 +1058,7 @@ static void gnttab_request_version(void)
> int rc;
> struct gnttab_set_version gsv;
>
> - if (xen_hvm_domain())
> + if (xen_hvm_domain() || xen_feature(XENFEAT_auto_translated_physmap))
> gsv.version = 1;
> else
> gsv.version = 2;
> @@ -1081,12 +1086,24 @@ static void gnttab_request_version(void)
> int gnttab_resume(void)
> {
> unsigned int max_nr_gframes;
> + char *kmsg="Failed to kmalloc pages for pv in hvm grant frames\n";
msg = "Failed
>
> gnttab_request_version();
> max_nr_gframes = gnttab_max_grant_frames();
> if (max_nr_gframes < nr_grant_frames)
> return -ENOSYS;
>
> + /* PVH note: xen will free existing kmalloc'd mfn in
> + * XENMEM_add_to_physmap */
> + if (xen_pv_domain() && xen_feature(XENFEAT_auto_translated_physmap) &&
> + !gnttab_shared.addr) {
> + gnttab_shared.addr =
> + kmalloc(max_nr_gframes * PAGE_SIZE, GFP_KERNEL);
> + if ( !gnttab_shared.addr ) {
if (!gnttab_shared.addr) {
> + printk(KERN_WARNING "%s", kmsg);
> + return -ENOMEM;
> + }
> + }
> if (xen_pv_domain())
> return gnttab_map(0, nr_grant_frames - 1);
>
> --
> 1.7.2.3
>
^ permalink raw reply [flat|nested] 5+ messages in thread