From: "Jan Beulich" <JBeulich@suse.com>
To: Shuai Ruan <shuai.ruan@linux.intel.com>
Cc: andrew.cooper3@citrix.com, xen-devel@lists.xen.org
Subject: Re: [PATCH V7 1/3] x86/xsaves: fix overwriting between non-lazy/lazy xsaves
Date: Mon, 25 Apr 2016 00:51:44 -0600 [thread overview]
Message-ID: <571DDAA002000078000E51A7@prv-mh.provo.novell.com> (raw)
In-Reply-To: <1459414657-7558-2-git-send-email-shuai.ruan@linux.intel.com>
>>> On 31.03.16 at 10:57, <shuai.ruan@linux.intel.com> wrote:
> +#define XRSTOR(pfx) \
> + if ( v->arch.xcr0_accum & XSTATE_XSAVES_ONLY ) \
> + { \
> + if ( unlikely(!(ptr->xsave_hdr.xcomp_bv & \
> + XSTATE_COMPACTION_ENABLED)) ) \
> + ptr->xsave_hdr.xcomp_bv |= ptr->xsave_hdr.xstate_bv | \
> + XSTATE_COMPACTION_ENABLED; \
From v5 to v6 this changed from just = to |=, without any
explanation, and without me really noticing - why? Weren't
the other changes done specifically to guarantee xcomp_bv
to be zero up to this point? In which case I'd prefer to make
this obvious/explicit, by using = and perhaps an ASSERT()
here. (I have a patch ready, but I'd like to understand if
there was a reason for this change that I don't see.)
Jan
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next prev parent reply other threads:[~2016-04-25 6:51 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-31 8:57 [PATCH V7 0/3] xsaves bug fix Shuai Ruan
2016-03-31 8:57 ` [PATCH V7 1/3] x86/xsaves: fix overwriting between non-lazy/lazy xsaves Shuai Ruan
2016-04-04 15:51 ` Jan Beulich
2016-04-05 5:30 ` Shuai Ruan
[not found] ` <20160405053023.GA16876@shuai.ruan@linux.intel.com>
2016-04-05 7:17 ` Jan Beulich
2016-04-05 7:29 ` Shuai Ruan
2016-04-25 6:51 ` Jan Beulich [this message]
2016-04-29 1:36 ` Shuai Ruan
[not found] ` <20160429013616.GB4359@shuai.ruan@linux.intel.com>
2016-04-29 7:05 ` Jan Beulich
2016-03-31 8:57 ` [PATCH V7 2/3] x86/xsaves: fix two remained issues Shuai Ruan
2016-04-04 16:03 ` Jan Beulich
2016-03-31 8:57 ` [PATCH V7 3/3] x86/xsaves: ebx may return wrong value using CPUID eax=0xdh, ecx =1 Shuai Ruan
2016-04-05 8:31 ` Jan Beulich
2016-04-06 7:01 ` Shuai Ruan
[not found] ` <20160406070034.GA26357@shuai.ruan@linux.intel.com>
2016-04-07 0:29 ` Jan Beulich
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