From: Julien Grall <julien.grall@linaro.org>
To: Ian Campbell <ian.campbell@citrix.com>, xen-devel@lists.xen.org
Cc: tim@xen.org, stefano.stabellini@eu.citrix.com
Subject: Re: [PATCH 6/9] xen: arm: Handle CP14 32-bit register accesses from userspace
Date: Tue, 09 Sep 2014 16:45:58 -0700 [thread overview]
Message-ID: <540F9136.3080903@linaro.org> (raw)
In-Reply-To: <1410279788-27167-6-git-send-email-ian.campbell@citrix.com>
Hi Ian,
On 09/09/14 09:23, Ian Campbell wrote:
> Accesses to these from 32-bit userspace would cause a hypervisor exception
> (host crash) when running a 64-bit kernel, which is worked around by the fix to
> XSA-102. On 32-bit kernels they would be implemented as RAZ/WI which is
> incorrect but harmless.
>
> Update as follows:
> - DBGDSCRINT should be R/O.
> - DBGDSCREXT should be EL1 only.
> - DBGOSLAR is RO and EL1 only.
> - DBGVCR, DBGB[VC]R*, DBGW[VC]R*, and DBGOSDLR are EL1 only.
>
> DBGDIDR and DBGDSCRINT are accessible from EL0 if DBGDSCRext.UDCCdis. Since we
> emulate that as RAZ/WI we allow access.
Shall we just set DBGDSCRext.UDCCdis to avoid taking care of EL0 access?
Regards,
--
Julien Grall
next prev parent reply other threads:[~2014-09-09 23:45 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-09 16:22 [RFC PATCH 0/9] xen: arm: reenable support for 32-bit userspace running in 64-bit guest Ian Campbell
2014-09-09 16:23 ` [PATCH 1/9] xen: arm: Correct PMXEV cp register definitions Ian Campbell
2014-09-09 23:04 ` Julien Grall
2014-09-09 16:23 ` [PATCH 2/9] xen: arm: Factor out psr_mode_is_user Ian Campbell
2014-09-09 23:08 ` Julien Grall
2014-09-09 16:23 ` [PATCH 3/9] xen: arm: Handle 32-bit EL0 on 64-bit EL1 when advancing PC after trap Ian Campbell
2014-09-09 23:12 ` Julien Grall
2014-09-09 16:23 ` [PATCH 4/9] xen: arm: turn vtimer traps for cp32/64 and sysreg into #undef Ian Campbell
2014-09-09 23:31 ` Julien Grall
2014-09-10 9:46 ` Ian Campbell
2014-09-10 18:54 ` Julien Grall
2014-09-11 8:43 ` Ian Campbell
2015-01-14 16:33 ` Ian Campbell
2015-01-14 16:57 ` Julien Grall
2015-01-15 10:26 ` Ian Campbell
2015-01-15 12:27 ` Julien Grall
2015-01-15 12:35 ` Ian Campbell
2014-09-09 16:23 ` [PATCH 5/9] xen: arm: Handle CP15 register traps from userspace Ian Campbell
2014-09-09 23:42 ` Julien Grall
2014-09-10 9:48 ` Ian Campbell
2014-09-10 18:56 ` Julien Grall
2014-09-18 1:31 ` Ian Campbell
2014-09-09 16:23 ` [PATCH 6/9] xen: arm: Handle CP14 32-bit register accesses " Ian Campbell
2014-09-09 23:45 ` Julien Grall [this message]
2014-09-10 9:48 ` Ian Campbell
2015-02-10 3:40 ` Ian Campbell
2015-02-10 4:14 ` Julien Grall
2014-09-09 16:23 ` [PATCH 7/9] xen: arm: correctly handle sysreg " Ian Campbell
2014-09-09 16:23 ` [PATCH 8/9] xen: arm: handle remaining traps " Ian Campbell
2014-09-09 16:23 ` [PATCH 9/9] xen: arm: Allow traps from 32 bit userspace on 64 bit hypervisors again Ian Campbell
2014-09-09 16:23 ` [RFC PATCH 0/9] xen: arm: reenable support for 32-bit userspace running in 64-bit guest Ian Campbell
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