From: Will Deacon <will.deacon@arm.com>
To: Zhichao Huang <zhichao.huang@linaro.org>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>,
Marc Zyngier <Marc.Zyngier@arm.com>,
"alex.bennee@linaro.org" <alex.bennee@linaro.org>,
Christoffer Dall <christoffer.dall@linaro.org>,
"huangzhichao@huawei.com" <huangzhichao@huawei.com>
Subject: Re: [PATCH v3 08/11] KVM: arm: implement dirty bit mechanism for debug registers
Date: Tue, 7 Jul 2015 11:24:06 +0100 [thread overview]
Message-ID: <20150707102405.GE23879@arm.com> (raw)
In-Reply-To: <5A7DE9A0-E7A6-40B0-80F9-896F7DED0E47@linaro.org>
On Tue, Jul 07, 2015 at 11:06:57AM +0100, Zhichao Huang wrote:
> Chazy and me are talking about how to reduce the saving/restoring
> overhead for debug registers.
> We want to add a state in hw_breakpoint.c to indicate whether the host
> enable any hwbrpts or not (might export a fuction that kvm can call),
> then we can read this state from memory instead of reading from real
> hardware registers, and to decide whether we need a world switch or
> not.
> Does it acceptable?
Maybe, hard to tell without the code. There are obvious races to deal with
if you use variables to indicate whether resources are in use -- why not
just trap debug access from the host as well? Then you could keep track of
the "owner" in kvm and trap accesses from everybody else.
Will
next prev parent reply other threads:[~2015-07-07 10:24 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-22 10:41 [PATCH v3 00/11] KVM: arm: debug infrastructure support Zhichao Huang
2015-06-22 10:41 ` [PATCH v3 01/11] KVM: arm: plug guest debug exploit Zhichao Huang
2015-06-29 15:49 ` Christoffer Dall
2015-07-01 7:04 ` zichao
2015-07-01 9:00 ` Christoffer Dall
2015-06-22 10:41 ` [PATCH v3 02/11] KVM: arm: rename pm_fake handler to trap_raz_wi Zhichao Huang
2015-06-30 13:20 ` Christoffer Dall
2015-06-22 10:41 ` [PATCH v3 03/11] KVM: arm: enable to use the ARM_DSCR_MDBGEN macro from KVM assembly code Zhichao Huang
2015-06-30 13:20 ` Christoffer Dall
2015-06-22 10:41 ` [PATCH v3 04/11] KVM: arm: common infrastructure for handling AArch32 CP14/CP15 Zhichao Huang
2015-06-29 19:43 ` Christoffer Dall
2015-07-01 7:09 ` zichao
2015-07-01 9:00 ` Christoffer Dall
2015-06-22 10:41 ` [PATCH v3 05/11] KVM: arm: check ordering of all system register tables Zhichao Huang
2015-06-30 13:20 ` Christoffer Dall
2015-06-22 10:41 ` [PATCH v3 06/11] KVM: arm: add trap handlers for 32-bit debug registers Zhichao Huang
2015-06-29 21:16 ` Christoffer Dall
2015-07-01 7:14 ` zichao
2015-06-22 10:41 ` [PATCH v3 07/11] KVM: arm: add trap handlers for 64-bit " Zhichao Huang
2015-06-30 13:20 ` Christoffer Dall
2015-07-01 7:43 ` Zhichao Huang
2015-06-22 10:41 ` [PATCH v3 08/11] KVM: arm: implement dirty bit mechanism for " Zhichao Huang
2015-06-30 9:20 ` Christoffer Dall
2015-07-03 9:54 ` Zhichao Huang
2015-07-03 11:56 ` Christoffer Dall
2015-07-07 10:06 ` Zhichao Huang
2015-07-07 10:24 ` Will Deacon [this message]
2015-07-08 10:50 ` Zhichao Huang
2015-07-08 17:08 ` Will Deacon
2015-07-09 12:54 ` Zhichao Huang
2015-07-09 11:50 ` Christoffer Dall
2015-07-13 12:12 ` zichao
2015-06-22 10:41 ` [PATCH v3 09/11] KVM: arm: implement lazy world switch " Zhichao Huang
2015-06-30 13:15 ` Christoffer Dall
2015-07-03 10:06 ` Zhichao Huang
2015-07-03 21:05 ` Christoffer Dall
2015-06-22 10:41 ` [PATCH v3 10/11] KVM: arm: add a trace event for cp14 traps Zhichao Huang
2015-06-30 13:20 ` Christoffer Dall
2015-06-22 10:41 ` [PATCH v3 11/11] KVM: arm: enable trapping of all debug registers Zhichao Huang
2015-06-30 13:19 ` Christoffer Dall
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