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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2 1/5] arm: shared_info page allocation and mapping
On Thu, 2012-02-23 at 18:21 +0000, Stefano Stabellini wrote:
> Allocate the shared_info page at domain creation.
>
> Implement arch_memory_op, only for XENMEM_add_to_physmap with space ==
> XENMAPSPACE_shared_info, so that the guest can map the shared_info page.
>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> ---
> xen/arch/arm/domain.c | 8 ++++
> xen/arch/arm/mm.c | 98
> +++++++++++++++++++++++++++++++++++++++++++--
> xen/arch/arm/p2m.c | 15 ++++++-
> xen/include/asm-arm/mm.h | 4 ++
> xen/include/asm-arm/p2m.h | 2 +
> 5 files changed, 122 insertions(+), 5 deletions(-)
>
> diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
> index 0b55934..0ee96b9 100644
> --- a/xen/arch/arm/domain.c
> +++ b/xen/arch/arm/domain.c
> @@ -235,6 +235,14 @@ int arch_domain_create(struct domain *d, unsigned int
> domcr_flags)
> if ( (rc = p2m_init(d)) != 0 )
> goto fail;
>
> + rc = -ENOMEM;
> + if ( (d->shared_info = alloc_xenheap_pages(0, MEMF_bits(32))) == NULL )
> + goto fail;
> +
> + clear_page(d->shared_info);
> + share_xen_page_with_guest(
> + virt_to_page(d->shared_info), d, XENSHARE_writable);
> +
> d->max_vcpus = 8;
>
> if ( (rc = domain_vgic_init(d)) != 0 )
> diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
> index a0f39eb..0fe0398 100644
> --- a/xen/arch/arm/mm.c
> +++ b/xen/arch/arm/mm.c
> @@ -25,8 +25,11 @@
> #include <xen/mm.h>
> #include <xen/preempt.h>
> #include <xen/errno.h>
> +#include <xen/guest_access.h>
> #include <asm/page.h>
> #include <asm/current.h>
> +#include <public/memory.h>
> +#include <xen/sched.h>
>
> struct domain *dom_xen, *dom_io;
>
> @@ -323,17 +326,104 @@ void arch_dump_shared_mem_info(void)
> {
> }
>
> -long arch_memory_op(int op, XEN_GUEST_HANDLE(void) arg)
> +int donate_page(struct domain *d, struct page_info *page, unsigned int
> memflags)
> {
> + ASSERT(0);
> return -ENOSYS;
> }
>
> -int donate_page(struct domain *d, struct page_info *page, unsigned int
> memflags)
> +void share_xen_page_with_guest(struct page_info *page,
> + struct domain *d, int readonly)
> {
> - ASSERT(0);
> - return -ENOSYS;
> + if ( page_get_owner(page) == d )
> + return;
> +
> + spin_lock(&d->page_alloc_lock);
> +
> + /* The incremented type count pins as writable or read-only. */
> + page->u.inuse.type_info = (readonly ? PGT_none : PGT_writable_page);
> + page->u.inuse.type_info |= PGT_validated | 1;
> +
> + page_set_owner(page, d);
> + wmb(); /* install valid domain ptr before updating refcnt. */
> + ASSERT((page->count_info & ~PGC_xen_heap) == 0);
> +
> + /* Only add to the allocation list if the domain isn't dying. */
> + if ( !d->is_dying )
> + {
> + page->count_info |= PGC_allocated | 1;
> + if ( unlikely(d->xenheap_pages++ == 0) )
> + get_knownalive_domain(d);
> + page_list_add_tail(page, &d->xenpage_list);
> + }
> +
> + spin_unlock(&d->page_alloc_lock);
> +}
> +
> +static int xenmem_add_to_physmap_once(
> + struct domain *d,
> + const struct xen_add_to_physmap *xatp)
> +{
> + unsigned long mfn = 0;
> + int rc;
> +
> + switch ( xatp->space )
> + {
> + case XENMAPSPACE_shared_info:
> + if ( xatp->idx == 0 )
> + mfn = virt_to_mfn(d->shared_info);
> + break;
> + default:
> + return -ENOSYS;
> + }
> +
> + domain_lock(d);
> +
> + /* Map at new location. */
> + rc = guest_physmap_add_page(d, xatp->gpfn, mfn);
> +
> + domain_unlock(d);
> +
> + return rc;
> +}
> +
> +static int xenmem_add_to_physmap(struct domain *d,
> + struct xen_add_to_physmap *xatp)
> +{
> + return xenmem_add_to_physmap_once(d, xatp);
> }
>
> +long arch_memory_op(int op, XEN_GUEST_HANDLE(void) arg)
> +{
> + int rc;
> +
> + switch ( op )
> + {
> + case XENMEM_add_to_physmap:
> + {
> + struct xen_add_to_physmap xatp;
> + struct domain *d;
> +
> + if ( copy_from_guest(&xatp, arg, 1) )
> + return -EFAULT;
> +
> + rc = rcu_lock_target_domain_by_id(xatp.domid, &d);
> + if ( rc != 0 )
> + return rc;
> +
> + rc = xenmem_add_to_physmap(d, &xatp);
> +
> + rcu_unlock_domain(d);
> +
> + return rc;
> + }
> +
> + default:
> + return -ENOSYS;
> + }
> +
> + return 0;
> +}
> /*
> * Local variables:
> * mode: C
> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
> index 14614fd..1a00a50 100644
> --- a/xen/arch/arm/p2m.c
> +++ b/xen/arch/arm/p2m.c
> @@ -118,7 +118,12 @@ static int create_p2m_entries(struct domain *d,
> }
> /* else: third already valid */
>
> - BUG_ON(third[third_table_offset(addr)].p2m.valid);
> + if ( third[third_table_offset(addr)].p2m.valid )
> + {
> + /* p2m entry already present */
> + free_domheap_page(
> + mfn_to_page(third[third_table_offset(addr)].p2m.base));
> + }
>
> /* Allocate a new RAM page and attach */
> if (alloc)
> @@ -172,6 +177,14 @@ int map_mmio_regions(struct domain *d,
> return create_p2m_entries(d, 0, start_gaddr, end_gaddr, maddr);
> }
>
> +int guest_physmap_add_page(struct domain *d, unsigned long gpfn,
> + unsigned long mfn)
> +{
> + return create_p2m_entries(d, 0, gpfn << PAGE_SHIFT,
> + (gpfn + 1) << PAGE_SHIFT,
> + mfn << PAGE_SHIFT);
> +}
> +
> int p2m_alloc_table(struct domain *d)
> {
> struct p2m_domain *p2m = &d->arch.p2m;
> diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
> index bfc0f76..56ab9415 100644
> --- a/xen/include/asm-arm/mm.h
> +++ b/xen/include/asm-arm/mm.h
> @@ -78,6 +78,10 @@ struct page_info
> #define _PGT_pinned PG_shift(5)
> #define PGT_pinned PG_mask(1, 5)
>
> + /* Has this page been validated for use as its current type? */
> +#define _PGT_validated PG_shift(6)
> +#define PGT_validated PG_mask(1, 6)
> +
> /* Count of uses of this frame as its current type. */
> #define PGT_count_width PG_shift(9)
> #define PGT_count_mask ((1UL<<PGT_count_width)-1)
> diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
> index aec52f7..c0f2995 100644
> --- a/xen/include/asm-arm/p2m.h
> +++ b/xen/include/asm-arm/p2m.h
> @@ -39,6 +39,8 @@ int p2m_populate_ram(struct domain *d, paddr_t start,
> paddr_t end);
> * address maddr. */
> int map_mmio_regions(struct domain *d, paddr_t start_gaddr,
> paddr_t end_gaddr, paddr_t maddr);
> +int guest_physmap_add_page(struct domain *d, unsigned long gpfn,
> + unsigned long mfn);
>
> unsigned long gmfn_to_mfn(struct domain *d, unsigned long gpfn);
>
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