| Message ID | 1387213237-1216-1-git-send-email-julien.grall@linaro.org |
|---|---|
| State | Superseded, archived |
| Headers | show |
>>> On 16.12.13 at 18:00, Julien Grall <julien.grall@linaro.org> wrote: > With the lack of iommu, dom0 must have a 1:1 memory mapping for all > these guest physical address. When the ballon decides to give back a > page to the kernel, this page must have the same address as previously. > Otherwise, we will loose the 1:1 mapping and will break DMA-capable > devices. > > Signed-off-by: Julien Grall <julien.grall@linaro.org> > Cc: Keir Fraser <keir@xen.org> Reviewed-by: Jan Beulich <jbeulich@suse.com> if you do one more change (and a little bit of further cleanup - sorry I didn't notice this before): > @@ -122,7 +126,29 @@ static void populate_physmap(struct memop_args *a) > } > else > { > - page = alloc_domheap_pages(d, a->extent_order, a->memflags); > + if ( is_domain_direct_mapped(d) ) > + { > + mfn = gpfn; > + if ( !mfn_valid(mfn) ) > + { > + gdprintk(XENLOG_INFO, "Invalid mfn 0x%"PRI_xen_pfn"\n", "... %#"PRI_xen_pfn"\n" please. > + mfn); > + goto out; > + } > + > + page = mfn_to_page(mfn); > + if ( !get_page(page, d) ) > + { > + gdprintk(XENLOG_INFO, > + "mfn 0x%"PRI_xen_pfn" doesn't belong to the" > + " domain\n", mfn); Same here. > --- a/xen/include/asm-arm/domain.h > +++ b/xen/include/asm-arm/domain.h > @@ -86,6 +86,9 @@ enum domain_type { > #define is_pv64_domain(d) (0) > #endif > > +extern int dom0_11_mapping; > +#define is_domain_direct_mapped(d) (dom0_11_mapping && (d) == dom0) This needs to be #define is_domain_direct_mapped(d) ((d) == dom0 && dom0_11_mapping) in order to make sure d is evaluated exactly once. Jan
On 12/17/2013 08:57 AM, Jan Beulich wrote: >>>> On 16.12.13 at 18:00, Julien Grall <julien.grall@linaro.org> wrote: >> With the lack of iommu, dom0 must have a 1:1 memory mapping for all >> these guest physical address. When the ballon decides to give back a >> page to the kernel, this page must have the same address as previously. >> Otherwise, we will loose the 1:1 mapping and will break DMA-capable >> devices. >> >> Signed-off-by: Julien Grall <julien.grall@linaro.org> >> Cc: Keir Fraser <keir@xen.org> > > Reviewed-by: Jan Beulich <jbeulich@suse.com> > if you do one more change (and a little bit of further cleanup - > sorry I didn't notice this before): Thanks, I will do all the changes.
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c index faff88e..47b781b 100644 --- a/xen/arch/arm/domain_build.c +++ b/xen/arch/arm/domain_build.c @@ -22,7 +22,7 @@ static unsigned int __initdata opt_dom0_max_vcpus; integer_param("dom0_max_vcpus", opt_dom0_max_vcpus); -static int dom0_11_mapping = 1; +int dom0_11_mapping = 1; #define DOM0_MEM_DEFAULT 0x8000000 /* 128 MiB */ static u64 __initdata dom0_mem = DOM0_MEM_DEFAULT; diff --git a/xen/common/memory.c b/xen/common/memory.c index eb7b72b..1a93196 100644 --- a/xen/common/memory.c +++ b/xen/common/memory.c @@ -29,6 +29,10 @@ #include <xsm/xsm.h> #include <xen/trace.h> +#ifndef is_domain_direct_mapped +# define is_domain_direct_mapped(d) ((void)(d), 0) +#endif + struct memop_args { /* INPUT */ struct domain *domain; /* Domain to be affected. */ @@ -122,7 +126,29 @@ static void populate_physmap(struct memop_args *a) } else { - page = alloc_domheap_pages(d, a->extent_order, a->memflags); + if ( is_domain_direct_mapped(d) ) + { + mfn = gpfn; + if ( !mfn_valid(mfn) ) + { + gdprintk(XENLOG_INFO, "Invalid mfn 0x%"PRI_xen_pfn"\n", + mfn); + goto out; + } + + page = mfn_to_page(mfn); + if ( !get_page(page, d) ) + { + gdprintk(XENLOG_INFO, + "mfn 0x%"PRI_xen_pfn" doesn't belong to the" + " domain\n", mfn); + goto out; + } + put_page(page); + } + else + page = alloc_domheap_pages(d, a->extent_order, a->memflags); + if ( unlikely(page == NULL) ) { if ( !opt_tmem || (a->extent_order != 0) ) @@ -270,6 +296,13 @@ static void decrease_reservation(struct memop_args *a) && p2m_pod_decrease_reservation(a->domain, gmfn, a->extent_order) ) continue; + /* With the lack for iommu on some ARM platform, domain with DMA-capable + * device must retrieve the same pfn when the hypercall + * populate_physmap is called. + */ + if ( is_domain_direct_mapped(a->domain) ) + continue; + for ( j = 0; j < (1 << a->extent_order); j++ ) if ( !guest_remove_page(a->domain, gmfn + j) ) goto out; diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h index 28d39a0..3419c31 100644 --- a/xen/include/asm-arm/domain.h +++ b/xen/include/asm-arm/domain.h @@ -86,6 +86,9 @@ enum domain_type { #define is_pv64_domain(d) (0) #endif +extern int dom0_11_mapping; +#define is_domain_direct_mapped(d) (dom0_11_mapping && (d) == dom0) + struct vtimer { struct vcpu *v; int irq;
With the lack of iommu, dom0 must have a 1:1 memory mapping for all these guest physical address. When the ballon decides to give back a page to the kernel, this page must have the same address as previously. Otherwise, we will loose the 1:1 mapping and will break DMA-capable devices. Signed-off-by: Julien Grall <julien.grall@linaro.org> Cc: Keir Fraser <keir@xen.org> Cc: Jan Beulich <jbeulich@suse.com> --- Release: This is a bug that prevents DMA-capable devices to work after a guest has started. Changes in v5: - Export dom0_11_mapping and transform is_domain_direct_mapped in macro - Add ifndef in common code to define is_domain_direct_mapped Changes in v4: - Fix typoes - Update comment in the code Changes in v3: - Remove spurious page = NULL - Rename is_dom0_mapped_11 to is_domain_direct_mapped - Coding style Changes in v2: - Drop CONFIG_ARM and add is_dom0_mapped_11 --- xen/arch/arm/domain_build.c | 2 +- xen/common/memory.c | 35 ++++++++++++++++++++++++++++++++++- xen/include/asm-arm/domain.h | 3 +++ 3 files changed, 38 insertions(+), 2 deletions(-)