Mukesh Rathor
2013-Feb-01 02:30 UTC
[PATCH] PVH linux: Use ballooning to allocate grant table pages
This patch fixes a fixme in Linux to use alloc_xenballooned_pages() to allocate pfns for grant table pages instead of kmalloc. This also simplifies add to physmap on the xen side a bit. Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com> --- drivers/xen/grant-table.c | 37 ++++++++++++++++++++++++++----------- 1 files changed, 26 insertions(+), 11 deletions(-) diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 9c0019d..d731f39 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -47,6 +47,7 @@ #include <xen/grant_table.h> #include <xen/interface/memory.h> #include <xen/hvc-console.h> +#include <xen/balloon.h> #include <asm/xen/hypercall.h> #include <asm/xen/interface.h> @@ -1138,27 +1139,41 @@ static void gnttab_request_version(void) grant_table_version); } +static int xlated_setup_gnttab_pages(int numpages, void **addr) +{ + int i, rc; + unsigned long pfns[numpages]; + struct page *pages[numpages]; + + rc = alloc_xenballooned_pages(numpages, pages, 0); + if (rc != 0) { + pr_warn("%s Could not balloon alloc %d pfns rc:%d\n", __func__, + numpages, rc); + return -ENOMEM; + } + for (i = 0; i < numpages; i++) + pfns[i] = page_to_pfn(pages[i]); + + rc = arch_gnttab_map_shared(pfns, numpages, numpages, addr); + return rc; +} + int gnttab_resume(void) { - unsigned int max_nr_gframes; - char *kmsg = "Failed to kmalloc pages for pv in hvm grant frames\n"; + unsigned int rc, max_nr_gframes; 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. TBD/FIXME: use xen ballooning instead of - * kmalloc(). */ 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) { - pr_warn("%s", kmsg); - return -ENOMEM; - } + + rc = xlated_setup_gnttab_pages(max_nr_gframes, + &gnttab_shared.addr); + if (rc != 0) + return rc; } if (xen_pv_domain()) return gnttab_map(0, nr_grant_frames - 1); -- 1.7.2.3
Mukesh Rathor
2013-Feb-01 02:44 UTC
Re: [Xen-devel] [PATCH] PVH linux: Use ballooning to allocate grant table pages
On Thu, 31 Jan 2013 18:30:15 -0800 Mukesh Rathor <mukesh.rathor@oracle.com> wrote:> This patch fixes a fixme in Linux to use alloc_xenballooned_pages() to > allocate pfns for grant table pages instead of kmalloc. This also > simplifies add to physmap on the xen side a bit.Looking at it again, I realized rc should be signed in gnttab_resume(). Below again. Thanks. Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 9c0019d..7a630bb 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -47,6 +47,7 @@ #include <xen/grant_table.h> #include <xen/interface/memory.h> #include <xen/hvc-console.h> +#include <xen/balloon.h> #include <asm/xen/hypercall.h> #include <asm/xen/interface.h> @@ -1138,27 +1139,42 @@ static void gnttab_request_version(void) grant_table_version); } +static int xlated_setup_gnttab_pages(int numpages, void **addr) +{ + int i, rc; + unsigned long pfns[numpages]; + struct page *pages[numpages]; + + rc = alloc_xenballooned_pages(numpages, pages, 0); + if (rc != 0) { + pr_warn("%s Could not balloon alloc %d pfns rc:%d\n", __func__, + numpages, rc); + return -ENOMEM; + } + for (i = 0; i < numpages; i++) + pfns[i] = page_to_pfn(pages[i]); + + rc = arch_gnttab_map_shared(pfns, numpages, numpages, addr); + return rc; +} + int gnttab_resume(void) { + int rc; 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. TBD/FIXME: use xen ballooning instead of - * kmalloc(). */ 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) { - pr_warn("%s", kmsg); - return -ENOMEM; - } + + rc = xlated_setup_gnttab_pages(max_nr_gframes, + &gnttab_shared.addr); + if (rc != 0) + return rc; } if (xen_pv_domain()) return gnttab_map(0, nr_grant_frames - 1);
Mukesh Rathor
2013-Feb-01 22:00 UTC
Re: [Xen-devel] [PATCH] PVH linux: Use ballooning to allocate grant table pages
On Thu, 31 Jan 2013 18:44:46 -0800 Mukesh Rathor <mukesh.rathor@oracle.com> wrote:> On Thu, 31 Jan 2013 18:30:15 -0800 > Mukesh Rathor <mukesh.rathor@oracle.com> wrote: > > > This patch fixes a fixme in Linux to use alloc_xenballooned_pages() > > to allocate pfns for grant table pages instead of kmalloc. This also > > simplifies add to physmap on the xen side a bit. > > Looking at it again, I realized rc should be signed in > gnttab_resume(). Below again. Thanks.Konrad, Please hold off on this patch. I discovered an issue on the domU side with this change. I''m currently investigating if it''s related. thanks, Mukesh
Mukesh Rathor
2013-Feb-01 23:51 UTC
Re: [Xen-devel] [PATCH] PVH linux: Use ballooning to allocate grant table pages
On Fri, 1 Feb 2013 14:00:58 -0800 Mukesh Rathor <mukesh.rathor@oracle.com> wrote:> On Thu, 31 Jan 2013 18:44:46 -0800 > Mukesh Rathor <mukesh.rathor@oracle.com> wrote: > > > On Thu, 31 Jan 2013 18:30:15 -0800 > > Mukesh Rathor <mukesh.rathor@oracle.com> wrote: > > > > > This patch fixes a fixme in Linux to use > > > alloc_xenballooned_pages() to allocate pfns for grant table pages > > > instead of kmalloc. This also simplifies add to physmap on the > > > xen side a bit. > > > > Looking at it again, I realized rc should be signed in > > gnttab_resume(). Below again. Thanks. > > Konrad, Please hold off on this patch. I discovered an issue on the > domU side with this change. I''m currently investigating if it''s > related.Ah right, I forgot the pfn''s from balloon may not be always contigous. Besides these are special pfns so to speak, so in gnttab_map() virt_to_pfn doesn''t work. I''m gonna have to create a separate gnttab map routine for pvh case, it appears. Shouldn''t be too bad tho. thanks, Mukesh
Mukesh Rathor
2013-Feb-05 22:55 UTC
[PATCH] PVH linux: Use ballooning to allocate grant table pages
This patch fixes a fixme in Linux to use alloc_xenballooned_pages() to allocate pfns for grant table pages instead of kmalloc. This also simplifies add to physmap on the xen side a bit. Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 9c0019d..fdb1d88 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -47,6 +47,7 @@ #include <xen/grant_table.h> #include <xen/interface/memory.h> #include <xen/hvc-console.h> +#include <xen/balloon.h> #include <asm/xen/hypercall.h> #include <asm/xen/interface.h> @@ -1026,10 +1027,22 @@ static void gnttab_unmap_frames_v2(void) arch_gnttab_unmap(grstatus, nr_status_frames(nr_grant_frames)); } +static xen_pfn_t pvh_get_grant_pfn(int grant_idx) +{ + unsigned long vaddr; + unsigned int level; + pte_t *pte; + + vaddr = (unsigned long)(gnttab_shared.addr) + grant_idx * PAGE_SIZE; + pte = lookup_address(vaddr, &level); + BUG_ON(pte == NULL); + return pte_mfn(*pte); +} + static int gnttab_map(unsigned int start_idx, unsigned int end_idx) { struct gnttab_setup_table setup; - unsigned long *frames, start_gpfn; + unsigned long *frames, start_gpfn = 0; unsigned int nr_gframes = end_idx + 1; int rc; @@ -1040,8 +1053,6 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx) 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. @@ -1050,7 +1061,11 @@ 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 = start_gpfn + i; + if (xen_hvm_domain()) + xatp.gpfn = start_gpfn + i; + else + xatp.gpfn = pvh_get_grant_pfn(i); + rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp); if (rc != 0) { printk(KERN_WARNING @@ -1138,27 +1153,51 @@ static void gnttab_request_version(void) grant_table_version); } +/* + * PVH: we need three things: virtual address, pfns, and mfns. The pfns + * are allocated via ballooning, then we call arch_gnttab_map_shared to + * allocate the VA and put pfn''s in the pte''s for the VA. The mfn''s are + * finally allocated in gnttab_map() by xen which also populates the P2M. + */ +static int xlated_setup_gnttab_pages(unsigned long numpages, void **addr) +{ + int i, rc; + unsigned long pfns[numpages]; + struct page *pages[numpages]; + + rc = alloc_xenballooned_pages(numpages, pages, 0); + if (rc != 0) { + pr_warn("%s Couldn''t balloon alloc %ld pfns rc:%d\n", __func__, + numpages, rc); + return rc; + } + for (i = 0; i < numpages; i++) + pfns[i] = page_to_pfn(pages[i]); + + rc = arch_gnttab_map_shared(pfns, numpages, numpages, addr); + if (rc != 0) + free_xenballooned_pages(numpages, pages); + + return rc; +} + int gnttab_resume(void) { + int rc; 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. TBD/FIXME: use xen ballooning instead of - * kmalloc(). */ 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) { - pr_warn("%s", kmsg); - return -ENOMEM; - } + + rc = xlated_setup_gnttab_pages((unsigned long)max_nr_gframes, + &gnttab_shared.addr); + if (rc != 0) + return rc; } if (xen_pv_domain()) return gnttab_map(0, nr_grant_frames - 1);
Konrad Rzeszutek Wilk
2013-Feb-06 15:49 UTC
Re: [PATCH] PVH linux: Use ballooning to allocate grant table pages
On Thu, Jan 31, 2013 at 06:30:15PM -0800, Mukesh Rathor wrote:> This patch fixes a fixme in Linux to use alloc_xenballooned_pages() to > allocate pfns for grant table pages instead of kmalloc. This also > simplifies add to physmap on the xen side a bit.Pulled this.> > Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com> > > --- > drivers/xen/grant-table.c | 37 ++++++++++++++++++++++++++----------- > 1 files changed, 26 insertions(+), 11 deletions(-) > > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c > index 9c0019d..d731f39 100644 > --- a/drivers/xen/grant-table.c > +++ b/drivers/xen/grant-table.c > @@ -47,6 +47,7 @@ > #include <xen/grant_table.h> > #include <xen/interface/memory.h> > #include <xen/hvc-console.h> > +#include <xen/balloon.h> > #include <asm/xen/hypercall.h> > #include <asm/xen/interface.h> > > @@ -1138,27 +1139,41 @@ static void gnttab_request_version(void) > grant_table_version); > } > > +static int xlated_setup_gnttab_pages(int numpages, void **addr) > +{ > + int i, rc; > + unsigned long pfns[numpages]; > + struct page *pages[numpages]; > + > + rc = alloc_xenballooned_pages(numpages, pages, 0); > + if (rc != 0) { > + pr_warn("%s Could not balloon alloc %d pfns rc:%d\n", __func__, > + numpages, rc); > + return -ENOMEM; > + } > + for (i = 0; i < numpages; i++) > + pfns[i] = page_to_pfn(pages[i]); > + > + rc = arch_gnttab_map_shared(pfns, numpages, numpages, addr); > + return rc; > +} > + > int gnttab_resume(void) > { > - unsigned int max_nr_gframes; > - char *kmsg = "Failed to kmalloc pages for pv in hvm grant frames\n"; > + unsigned int rc, max_nr_gframes; > > 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. TBD/FIXME: use xen ballooning instead of > - * kmalloc(). */ > 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) { > - pr_warn("%s", kmsg); > - return -ENOMEM; > - } > + > + rc = xlated_setup_gnttab_pages(max_nr_gframes, > + &gnttab_shared.addr); > + if (rc != 0) > + return rc; > } > if (xen_pv_domain()) > return gnttab_map(0, nr_grant_frames - 1); > -- > 1.7.2.3 >
Mukesh Rathor
2013-Feb-06 21:31 UTC
Re: [PATCH] PVH linux: Use ballooning to allocate grant table pages
On Wed, 6 Feb 2013 10:49:13 -0500 Konrad Rzeszutek Wilk <konrad@darnok.org> wrote:> On Thu, Jan 31, 2013 at 06:30:15PM -0800, Mukesh Rathor wrote: > > This patch fixes a fixme in Linux to use alloc_xenballooned_pages() > > to allocate pfns for grant table pages instead of kmalloc. This also > > simplifies add to physmap on the xen side a bit. > > Pulled this. > >Konrad, no, there was a follow up email on this thread to discard this. Please discard this. I resent yesterday with proper fixes. I realize now I should''ve given one yesterday version number. My bad, this head cold is crippling my brain :).. Sorry for the confusion. Mukesh Following is the latest patch I emailed yesterday : This patch fixes a fixme in Linux to use alloc_xenballooned_pages() to allocate pfns for grant table pages instead of kmalloc. This also simplifies add to physmap on the xen side a bit. Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 9c0019d..fdb1d88 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -47,6 +47,7 @@ #include <xen/grant_table.h> #include <xen/interface/memory.h> #include <xen/hvc-console.h> +#include <xen/balloon.h> #include <asm/xen/hypercall.h> #include <asm/xen/interface.h> @@ -1026,10 +1027,22 @@ static void gnttab_unmap_frames_v2(void) arch_gnttab_unmap(grstatus, nr_status_frames(nr_grant_frames)); } +static xen_pfn_t pvh_get_grant_pfn(int grant_idx) +{ + unsigned long vaddr; + unsigned int level; + pte_t *pte; + + vaddr = (unsigned long)(gnttab_shared.addr) + grant_idx * PAGE_SIZE; + pte = lookup_address(vaddr, &level); + BUG_ON(pte == NULL); + return pte_mfn(*pte); +} + static int gnttab_map(unsigned int start_idx, unsigned int end_idx) { struct gnttab_setup_table setup; - unsigned long *frames, start_gpfn; + unsigned long *frames, start_gpfn = 0; unsigned int nr_gframes = end_idx + 1; int rc; @@ -1040,8 +1053,6 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx) 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. @@ -1050,7 +1061,11 @@ 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 = start_gpfn + i; + if (xen_hvm_domain()) + xatp.gpfn = start_gpfn + i; + else + xatp.gpfn = pvh_get_grant_pfn(i); + rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp); if (rc != 0) { printk(KERN_WARNING @@ -1138,27 +1153,51 @@ static void gnttab_request_version(void) grant_table_version); } +/* + * PVH: we need three things: virtual address, pfns, and mfns. The pfns + * are allocated via ballooning, then we call arch_gnttab_map_shared to + * allocate the VA and put pfn''s in the pte''s for the VA. The mfn''s are + * finally allocated in gnttab_map() by xen which also populates the P2M. + */ +static int xlated_setup_gnttab_pages(unsigned long numpages, void **addr) +{ + int i, rc; + unsigned long pfns[numpages]; + struct page *pages[numpages]; + + rc = alloc_xenballooned_pages(numpages, pages, 0); + if (rc != 0) { + pr_warn("%s Couldn''t balloon alloc %ld pfns rc:%d\n", __func__, + numpages, rc); + return rc; + } + for (i = 0; i < numpages; i++) + pfns[i] = page_to_pfn(pages[i]); + + rc = arch_gnttab_map_shared(pfns, numpages, numpages, addr); + if (rc != 0) + free_xenballooned_pages(numpages, pages); + + return rc; +} + int gnttab_resume(void) { + int rc; 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. TBD/FIXME: use xen ballooning instead of - * kmalloc(). */ 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) { - pr_warn("%s", kmsg); - return -ENOMEM; - } + + rc = xlated_setup_gnttab_pages((unsigned long)max_nr_gframes, + &gnttab_shared.addr); + if (rc != 0) + return rc; } if (xen_pv_domain()) return gnttab_map(0, nr_grant_frames - 1);