From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: "Sergey Dyasli" <sergey.dyasli@citrix.com>,
"Roger Pau Monné" <roger.pau@citrix.com>,
"Wei Liu" <wei.liu2@citrix.com>,
"Jan Beulich" <JBeulich@suse.com>,
Xen-devel <xen-devel@lists.xen.org>
Subject: Re: [PATCH v2 4/5] x86/hvm: Handle x2apic MSRs via the new guest_{rd, wr}msr() infrastructure
Date: Wed, 7 Mar 2018 15:59:49 -0500 [thread overview]
Message-ID: <20180307205949.GH23411@char.us.oracle.com> (raw)
In-Reply-To: <1520449116-15443-5-git-send-email-andrew.cooper3@citrix.com>
On Wed, Mar 07, 2018 at 06:58:35PM +0000, Andrew Cooper wrote:
> Dispatch from the guest_{rd,wr}msr() functions. The read side should be safe
> outside of current context, but the write side is definitely not. As the
> toolstack has no legitimate reason to access the APIC registers via this
> interface (not least because whether they are accessible at all depends on
> guest settings), unilaterally reject access attempts outside of current
> context.
>
> Rename to guest_{rd,wr}msr_x2apic() for consistency, and alter the functions
> to use X86EMUL_EXCEPTION rather than X86EMUL_UNHANDLEABLE. The previous
> callers turned UNHANDLEABLE into EXCEPTION, but using UNHANDLEABLE will now
> interfere with the fallback to legacy MSR handling.
>
> While altering guest_rdmsr_x2apic() make a couple of minor improvements.
> Reformat the initialiser for readable[] so it indents in a more natural way,
> and alter high to be a 64bit integer to avoid shifting 0 by 32 in the common
> path.
>
> Observant people might notice that we now don't let PV guests read the x2apic
> MSRs. They should never have been able to in the first place.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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next prev parent reply other threads:[~2018-03-07 20:59 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-07 18:58 [PATCH v2 0/5] x86: Switch some bits of MSR handing over to the new infrastructure Andrew Cooper
2018-03-07 18:58 ` [PATCH v2 1/5] x86/hvm: Handle viridian MSRs via the new guest_{rd, wr}msr() infrastructure Andrew Cooper
2018-03-13 15:00 ` Jan Beulich
2018-03-13 15:20 ` Jan Beulich
2018-03-13 15:47 ` Andrew Cooper
2018-03-13 16:25 ` Jan Beulich
2018-03-07 18:58 ` [PATCH v2 2/5] x86: Handle the Xen " Andrew Cooper
2018-03-13 15:04 ` Jan Beulich
2018-09-07 14:30 ` Andrew Cooper
2018-09-07 15:47 ` Jan Beulich
2018-09-07 16:01 ` Andrew Cooper
2018-09-10 9:44 ` Jan Beulich
2018-03-07 18:58 ` [PATCH v2 3/5] x86: Fix APIC MSR constant names Andrew Cooper
2018-03-07 20:59 ` Konrad Rzeszutek Wilk
2018-03-08 1:26 ` Tian, Kevin
2018-03-13 15:15 ` Jan Beulich
2018-09-10 14:39 ` Roger Pau Monné
2018-03-07 18:58 ` [PATCH v2 4/5] x86/hvm: Handle x2apic MSRs via the new guest_{rd, wr}msr() infrastructure Andrew Cooper
2018-03-07 20:59 ` Konrad Rzeszutek Wilk [this message]
2018-03-13 15:21 ` Jan Beulich
2018-09-10 14:45 ` Roger Pau Monné
2018-03-07 18:58 ` [PATCH v2 5/5] x86/msr: Blacklist various MSRs which guests definitely shouldn't be using Andrew Cooper
2018-03-07 21:01 ` Konrad Rzeszutek Wilk
2018-03-13 15:35 ` Jan Beulich
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