From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: Xen-devel <xen-devel@lists.xenproject.org>,
"Wei Liu" <wl@xen.org>, "Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [Xen-devel] [PATCH] x86/cpuid: Fix handling of the CPUID.7[0].eax levelling MSR
Date: Tue, 10 Sep 2019 11:26:30 +0100 [thread overview]
Message-ID: <ef4b2f5c-fe07-215e-638f-bd21bf9ec064@citrix.com> (raw)
In-Reply-To: <ba415d32-3b4e-1ac5-2968-ab01d526de00@suse.com>
On 10/09/2019 11:24, Jan Beulich wrote:
> On 09.09.2019 17:51, Andrew Cooper wrote:
>> --- a/xen/arch/x86/domctl.c
>> +++ b/xen/arch/x86/domctl.c
>> @@ -218,11 +218,16 @@ static int update_domain_cpuid_info(struct domain *d,
>> if ( is_pv_domain(d) && ((levelling_caps & LCAP_7ab0) == LCAP_7ab0) )
>> {
>> uint64_t mask = cpuidmask_defaults._7ab0;
>> - uint32_t eax = ctl->eax;
>> - uint32_t ebx = p->feat._7b0;
>>
>> - if ( boot_cpu_data.x86_vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON) )
>> - mask &= ((uint64_t)eax << 32) | ebx;
>> + /*
>> + * Leaf 7[0].eax is max_subleaf, not a feature mask. Take it
>> + * wholesale from the policy, but clamp the features in 7[0].ebx
>> + * per usual.
>> + */
>> + if ( boot_cpu_data.x86_vendor &
>> + (X86_VENDOR_AMD | X86_VENDOR_HYGON) )
>> + mask = (((uint64_t)p->feat.max_subleaf << 32) |
>> + ((uint32_t)mask | p->feat._7b0));
> Assuming you mean & instead of | here, with it fixed
Oops - I do.
> Reviewed-by: Jan Beulich <jbeulich@suse.com>
Thanks,
~Andrew
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prev parent reply other threads:[~2019-09-10 10:26 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-09 15:51 [Xen-devel] [PATCH] x86/cpuid: Fix handling of the CPUID.7[0].eax levelling MSR Andrew Cooper
2019-09-10 9:29 ` Roger Pau Monné
2019-09-10 9:35 ` Andrew Cooper
2019-09-10 9:57 ` Roger Pau Monné
2019-09-10 10:25 ` Andrew Cooper
2019-09-10 10:24 ` Jan Beulich
2019-09-10 10:26 ` Andrew Cooper [this message]
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