From: Stefano Stabellini <sstabellini@kernel.org>
To: Julien Grall <julien.grall@arm.com>
Cc: proskurin@sec.in.tum.de, sstabellini@kernel.org,
steve.capper@arm.com, wei.chen@linaro.org,
xen-devel@lists.xen.org
Subject: Re: [PATCH 03/22] xen/arm: p2m: Restrict usage of get_page_from_gva to the current vCPU
Date: Thu, 21 Jul 2016 18:25:53 -0700 (PDT) [thread overview]
Message-ID: <alpine.DEB.2.10.1607211825470.6667@sstabellini-ThinkPad-X260> (raw)
In-Reply-To: <1469031064-23344-4-git-send-email-julien.grall@arm.com>
On Wed, 20 Jul 2016, Julien Grall wrote:
> The function get_page_from_gva translates a guest virtual address to a
> machine address. The translation involves the register VTTBR_EL2,
> TTBR0_EL1, TTBR1_EL1 and SCTLR_EL1.
>
> Currently, only the first register is context switch is the current
> domain is not the same. This will result to use the wrong TTBR*_EL1 and
> SCTLR_EL1 for the translation.
>
> To fix the code properly, we would have to context switch all the
> registers mentioned above when the vCPU in parameter is not the current
> one. Similar things would need to be done in the callee
> p2m_mem_check_and_get_page.
>
> Given that the only caller of this function with the vCPU that may not
> be current is a guest debugging function (show_guest_stack), restrict
> the usage to the current vCPU for the time being.
>
> A proper fix will be send separately.
>
> Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
> ---
> This patch is candidate to be backported up to Xen 4.5.
> ---
> xen/arch/arm/p2m.c | 24 ++++++++----------------
> 1 file changed, 8 insertions(+), 16 deletions(-)
>
> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
> index 1111d6f..64d84cc 100644
> --- a/xen/arch/arm/p2m.c
> +++ b/xen/arch/arm/p2m.c
> @@ -1530,24 +1530,16 @@ struct page_info *get_page_from_gva(struct vcpu *v, vaddr_t va,
> paddr_t maddr = 0;
> int rc;
>
> - spin_lock(&p2m->lock);
> -
> - if ( unlikely(d != current->domain) )
> - {
> - unsigned long irq_flags;
> -
> - local_irq_save(irq_flags);
> - p2m_load_VTTBR(d);
> + /*
> + * XXX: To support a different vCPU, we would need to load the
> + * VTTBR_EL2, TTBR0_EL1, TTBR1_EL1 and SCTLR_EL1
> + */
> + if ( v != current )
> + return NULL;
>
> - rc = gvirt_to_maddr(va, &maddr, flags);
> + spin_lock(&p2m->lock);
>
> - p2m_load_VTTBR(current->domain);
> - local_irq_restore(irq_flags);
> - }
> - else
> - {
> - rc = gvirt_to_maddr(va, &maddr, flags);
> - }
> + rc = gvirt_to_maddr(va, &maddr, flags);
>
> if ( rc )
> goto err;
> --
> 1.9.1
>
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next prev parent reply other threads:[~2016-07-22 1:25 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 [this message]
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
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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