linux-kernel - Re: [PATCH 1/3] KVM: trace mmio read event properly

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4F13F967.5000007@redhat.com>
Date:	Mon, 16 Jan 2012 12:18:15 +0200
From:	Avi Kivity <avi@...hat.com>
To:	Xiao Guangrong <xiaoguangrong@...ux.vnet.ibm.com>
CC:	Marcelo Tosatti <mtosatti@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>, KVM <kvm@...r.kernel.org>
Subject: Re: [PATCH 1/3] KVM: trace mmio read event properly

On 01/16/2012 11:31 AM, Xiao Guangrong wrote:
> In current code, we use KVM_TRACE_MMIO_READ to trace mmio read event which
> only can be completed immediately, instead of it, we trace the time when
> read event occur, then cooperate with then later patch, we can know the time
> of mmio read emulation
>
> @@ -3744,6 +3740,8 @@ mmio:
>  	/*
>  	 * Is this MMIO handled locally?
>  	 */
> +	trace_kvm_mmio(write ? KVM_TRACE_MMIO_WRITE : KVM_TRACE_MMIO_READ,

It's better to push the conditional to the trace event itself, so it's
only evaluated if tracing is enabled.

> +			bytes, gpa, *(u64 *)val);

We get the wrong value for reads here, no?

Can't we leave the code as is, and infer the start of the event from the
last kvm_exit trace?

>  	handled = ops->read_write_mmio(vcpu, gpa, bytes, val);
>  	if (handled == bytes)
>  		return X86EMUL_CONTINUE;


-- 
error compiling committee.c: too many arguments to function

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/