From: Stefano Stabellini <sstabellini@kernel.org>
To: Julien Grall <julien.grall@arm.com>
Cc: proskurin@sec.in.tum.de,
Stefano Stabellini <sstabellini@kernel.org>,
steve.capper@arm.com, wei.chen@linaro.org,
xen-devel@lists.xen.org
Subject: Re: [PATCH 09/22] xen/arm: p2m: Use a whitelist rather than blacklist in get_page_from_gfn
Date: Wed, 27 Jul 2016 10:56:25 -0700 (PDT) [thread overview]
Message-ID: <alpine.DEB.2.10.1607271055430.12319@sstabellini-ThinkPad-X260> (raw)
In-Reply-To: <b7c6c27c-edcc-8332-bfd0-41317ae7e639@arm.com>
On Wed, 27 Jul 2016, Julien Grall wrote:
> On 26/07/16 23:44, Stefano Stabellini wrote:
> > On Wed, 20 Jul 2016, Julien Grall wrote:
> > > Currently, the check in get_page_from_gfn is using a blacklist. This is
> > > very fragile because we may forgot to update the check when a new p2m
> > > type is added.
> > >
> > > To avoid any possible issue, use a whitelist. All type backed by a RAM
> > > page can could potential be valid. The check is borrowed from x86.
> > >
> > > Signed-off-by: Julien Grall <julien.grall@arm.com>
> > > ---
> > > xen/include/asm-arm/p2m.h | 9 ++++++++-
> > > 1 file changed, 8 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
> > > index 3091c04..78d37ab 100644
> > > --- a/xen/include/asm-arm/p2m.h
> > > +++ b/xen/include/asm-arm/p2m.h
> > > @@ -104,9 +104,16 @@ typedef enum {
> > > #define P2M_RAM_TYPES (p2m_to_mask(p2m_ram_rw) | \
> > > p2m_to_mask(p2m_ram_ro))
> > >
> > > +/* Grant mapping types, which map to a real frame in another VM */
> > > +#define P2M_GRANT_TYPES (p2m_to_mask(p2m_grant_map_rw) | \
> > > + p2m_to_mask(p2m_grant_map_ro))
> > > +
> > > /* Useful predicates */
> > > #define p2m_is_ram(_t) (p2m_to_mask(_t) & P2M_RAM_TYPES)
> > > #define p2m_is_foreign(_t) (p2m_to_mask(_t) &
> > > p2m_to_mask(p2m_map_foreign))
> > > +#define p2m_is_any_ram(_t) (p2m_to_mask(_t) & \
> > > + (P2M_RAM_TYPES | P2M_GRANT_TYPES | \
> > > + p2m_to_mask(p2m_map_foreign)))
> > >
> > > static inline
> > > void p2m_mem_access_emulate_check(struct vcpu *v,
> > > @@ -224,7 +231,7 @@ static inline struct page_info *get_page_from_gfn(
> > > if (t)
> > > *t = p2mt;
> > >
> > > - if ( p2mt == p2m_invalid || p2mt == p2m_mmio_direct )
> > > + if ( !p2m_is_any_ram(p2mt) )
> > > return NULL;
> >
> > What about the iommu mappings?
>
> iommu mappings (p2m_iommu_map_*) are special mappings for the direct mapping
> workaround. They should not be used in get_page_from_gfn.
Make sense. I think they deserve to be mentioned in the commit message,
as this patch changes behavior for them.
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next prev parent reply other threads:[~2016-07-27 17:56 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-20 16:10 [PATCH 00/22] xen/arm: P2M clean-up and fixes Julien Grall
2016-07-20 16:10 ` [PATCH 01/22] xen/arm: system: Use the correct parameter name in local_irq_restore Julien Grall
2016-07-22 1:19 ` Stefano Stabellini
2016-07-20 16:10 ` [PATCH 02/22] xen/arm: p2m: Pass the vCPU in parameter to get_page_from_gva Julien Grall
2016-07-22 1:22 ` Stefano Stabellini
2016-07-20 16:10 ` [PATCH 03/22] xen/arm: p2m: Restrict usage of get_page_from_gva to the current vCPU Julien Grall
2016-07-22 1:25 ` Stefano Stabellini
2016-07-20 16:10 ` [PATCH 04/22] xen/arm: p2m: Fix multi-lines coding style comments Julien Grall
2016-07-22 1:26 ` Stefano Stabellini
2016-07-20 16:10 ` [PATCH 05/22] xen/arm: p2m: Clean-up mfn_to_p2m_entry Julien Grall
2016-07-26 22:24 ` Stefano Stabellini
2016-07-20 16:10 ` [PATCH 06/22] xen/arm: p2m: Use the typesafe MFN in mfn_to_p2m_entry Julien Grall
2016-07-26 22:28 ` Stefano Stabellini
2016-07-27 9:54 ` Julien Grall
2016-07-27 18:25 ` Stefano Stabellini
2016-07-27 20:14 ` Julien Grall
2016-07-20 16:10 ` [PATCH 07/22] xen/arm: p2m: Use p2m_is_foreign in get_page_from_gfn to avoid open coding Julien Grall
2016-07-26 22:33 ` Stefano Stabellini
2016-07-20 16:10 ` [PATCH 08/22] xen/arm: p2m: Simplify p2m type check by using bitmask Julien Grall
2016-07-26 22:36 ` Stefano Stabellini
2016-07-20 16:10 ` [PATCH 09/22] xen/arm: p2m: Use a whitelist rather than blacklist in get_page_from_gfn Julien Grall
2016-07-26 22:44 ` Stefano Stabellini
2016-07-27 9:59 ` Julien Grall
2016-07-27 17:56 ` Stefano Stabellini [this message]
2016-07-27 17:57 ` Julien Grall
2016-07-20 16:10 ` [PATCH 10/22] xen/arm: p2m: Differentiate cacheable vs non-cacheable MMIO Julien Grall
2016-07-26 22:47 ` Stefano Stabellini
2016-07-20 16:10 ` [PATCH 11/22] xen/arm: p2m: Find the memory attributes based on the p2m type Julien Grall
2016-07-27 0:41 ` Stefano Stabellini
2016-07-27 17:15 ` Julien Grall
2016-07-27 17:55 ` Stefano Stabellini
2016-07-27 20:15 ` Julien Grall
2016-07-20 16:10 ` [PATCH 12/22] xen/arm: p2m: Remove unnecessary locking Julien Grall
2016-07-27 0:47 ` Stefano Stabellini
2016-07-20 16:10 ` [PATCH 13/22] xen/arm: p2m: Introduce p2m_{read, write}_{, un}lock helpers Julien Grall
2016-07-27 0:50 ` Stefano Stabellini
2016-07-20 16:10 ` [PATCH 14/22] xen/arm: p2m: Switch the p2m lock from spinlock to rwlock Julien Grall
2016-07-27 0:51 ` Stefano Stabellini
2016-07-20 16:10 ` [PATCH 15/22] xen/arm: Don't call p2m_alloc_table from arch_domain_create Julien Grall
2016-07-22 8:32 ` Sergej Proskurin
2016-07-22 9:18 ` Julien Grall
2016-07-22 10:16 ` Sergej Proskurin
2016-07-22 10:26 ` Julien Grall
2016-07-22 10:39 ` Sergej Proskurin
2016-07-22 10:38 ` Julien Grall
2016-07-22 11:05 ` Sergej Proskurin
2016-07-22 13:00 ` Julien Grall
2016-07-23 17:59 ` Sergej Proskurin
2016-07-27 0:54 ` Stefano Stabellini
2016-07-20 16:10 ` [PATCH 16/22] xen/arm: p2m: Move the vttbr field from arch_domain to p2m_domain Julien Grall
2016-07-22 7:46 ` Sergej Proskurin
2016-07-22 9:23 ` Julien Grall
2016-07-27 0:57 ` Stefano Stabellini
2016-07-27 10:00 ` Julien Grall
2016-07-27 17:19 ` Julien Grall
2016-07-20 16:10 ` [PATCH 17/22] xen/arm: p2m: Don't need to restore the state for an idle vCPU Julien Grall
2016-07-22 7:37 ` Sergej Proskurin
2016-07-27 1:05 ` Stefano Stabellini
2016-07-20 16:11 ` [PATCH 18/22] xen/arm: p2m: Rework the context switch to another VTTBR in flush_tlb_domain Julien Grall
2016-07-22 7:51 ` Sergej Proskurin
2016-07-27 1:12 ` Stefano Stabellini
2016-07-27 10:22 ` Julien Grall
2016-07-20 16:11 ` [PATCH 19/22] xen/arm: p2m: Inline p2m_load_VTTBR into p2m_restore_state Julien Grall
2016-07-22 8:07 ` Sergej Proskurin
2016-07-22 9:29 ` Julien Grall
2016-07-27 1:13 ` Stefano Stabellini
2016-07-20 16:11 ` [PATCH 20/22] xen/arm: Don't export flush_tlb_domain Julien Grall
2016-07-22 8:54 ` Sergej Proskurin
2016-07-22 9:30 ` Julien Grall
2016-07-22 10:25 ` Sergej Proskurin
2016-07-22 10:34 ` Julien Grall
2016-07-22 10:46 ` Sergej Proskurin
2016-07-22 10:57 ` Julien Grall
2016-07-22 11:22 ` Sergej Proskurin
2016-07-27 1:14 ` Stefano Stabellini
2016-07-20 16:11 ` [PATCH 21/22] xen/arm: p2m: Replace flush_tlb_domain by p2m_flush_tlb Julien Grall
2016-07-27 1:15 ` Stefano Stabellini
2016-07-20 16:11 ` [PATCH 22/22] xen/arm: p2m: Pass the p2m in parameter rather the domain when it is possible Julien Grall
2016-07-27 1:15 ` Stefano Stabellini
2016-07-22 1:31 ` [PATCH 00/22] xen/arm: P2M clean-up and fixes Stefano Stabellini
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