kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 23/61] KVM: x86: Clear output regs for CPUID 0x14 if PT isn't exposed to guest
Date: Fri, 21 Feb 2020 16:36:00 +0100	[thread overview]
Message-ID: <87eeuoq7fj.fsf@vitty.brq.redhat.com> (raw)
In-Reply-To: <20200201185218.24473-24-sean.j.christopherson@intel.com>

Sean Christopherson <sean.j.christopherson@intel.com> writes:

> Clear the output regs for the main CPUID 0x14 leaf (index=0) if Intel PT
> isn't exposed to the guest.  Leaf 0x14 enumerates Intel PT capabilities
> and should return zeroes if PT is not supported.  Incorrectly reporting
> PT capabilities is essentially a cosmetic error, i.e. doesn't negatively
> affect any known userspace/kernel, as the existence of PT itself is
> correctly enumerated via CPUID 0x7.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> ---
>  arch/x86/kvm/cpuid.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index d3c93b94abc3..056faf27b14b 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -663,8 +663,10 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
>  		break;
>  	/* Intel PT */
>  	case 0x14:
> -		if (!f_intel_pt)
> +		if (!f_intel_pt) {
> +			entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
>  			break;
> +		}
>  
>  		for (i = 1, max_idx = entry->eax; i <= max_idx; ++i) {
>  			if (!do_host_cpuid(array, function, i))

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>

-- 
Vitaly


  reply	other threads:[~2020-02-21 15:36 UTC|newest]

Thread overview: 168+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-01 18:51 [PATCH 00/61] KVM: x86: Introduce KVM cpu caps Sean Christopherson
2020-02-01 18:51 ` [PATCH 01/61] KVM: x86: Return -E2BIG when KVM_GET_SUPPORTED_CPUID hits max entries Sean Christopherson
2020-02-03 12:55   ` Vitaly Kuznetsov
2020-02-03 15:59     ` Sean Christopherson
2020-02-25 14:36       ` Paolo Bonzini
2020-02-01 18:51 ` [PATCH 02/61] KVM: x86: Refactor loop around do_cpuid_func() to separate helper Sean Christopherson
2020-02-06 14:59   ` Vitaly Kuznetsov
2020-02-07 19:53     ` Sean Christopherson
2020-02-25 14:37       ` Paolo Bonzini
2020-02-25 15:09         ` Vitaly Kuznetsov
2020-02-26 11:35           ` Paolo Bonzini
2020-02-01 18:51 ` [PATCH 03/61] KVM: x86: Simplify handling of Centaur CPUID leafs Sean Christopherson
2020-02-06 15:05   ` Vitaly Kuznetsov
2020-02-07 19:47     ` Sean Christopherson
2020-02-01 18:51 ` [PATCH 04/61] KVM: x86: Clean up error handling in kvm_dev_ioctl_get_cpuid() Sean Christopherson
2020-02-06 15:09   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 05/61] KVM: x86: Check userapce CPUID array size after validating sub-leaf Sean Christopherson
2020-02-06 15:24   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 06/61] KVM: x86: Move CPUID 0xD.1 handling out of the index>0 loop Sean Christopherson
2020-02-07 15:38   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 07/61] KVM: x86: Check for CPUID 0xD.N support before validating array size Sean Christopherson
2020-02-07 15:48   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 08/61] KVM: x86: Warn on zero-size save state for valid CPUID 0xD.N sub-leaf Sean Christopherson
2020-02-07 15:54   ` Vitaly Kuznetsov
2020-02-07 15:56     ` Sean Christopherson
2020-02-01 18:51 ` [PATCH 09/61] KVM: x86: Refactor CPUID 0xD.N sub-leaf entry creation Sean Christopherson
2020-02-07 15:56   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 10/61] KVM: x86: Clean up CPUID 0x7 sub-leaf loop Sean Christopherson
2020-02-21 14:20   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 11/61] KVM: x86: Drop the explicit @index from do_cpuid_7_mask() Sean Christopherson
2020-02-21 14:22   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 12/61] KVM: x86: Drop redundant boot cpu checks on SSBD feature bits Sean Christopherson
2020-02-01 18:51 ` [PATCH 13/61] KVM: x86: Consolidate CPUID array max num entries checking Sean Christopherson
2020-02-01 18:51 ` [PATCH 14/61] KVM: x86: Hoist loop counter and terminator to top of __do_cpuid_func() Sean Christopherson
2020-02-01 18:51 ` [PATCH 15/61] KVM: x86: Refactor CPUID 0x4 and 0x8000001d handling Sean Christopherson
2020-02-21 14:40   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 16/61] KVM: x86: Encapsulate CPUID entries and metadata in struct Sean Christopherson
2020-02-21 14:58   ` Vitaly Kuznetsov
2020-02-24 21:55     ` Sean Christopherson
2020-02-24 23:12       ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 17/61] KVM: x86: Drop redundant array size check Sean Christopherson
2020-02-01 18:51 ` [PATCH 18/61] KVM: x86: Use common loop iterator when handling CPUID 0xD.N Sean Christopherson
2020-02-21 15:04   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 19/61] KVM: VMX: Add helpers to query Intel PT mode Sean Christopherson
     [not found]   ` <87pne8q8c0.fsf@vitty.brq.redhat.com>
2020-02-24 22:18     ` Sean Christopherson
2020-02-25 14:54       ` Paolo Bonzini
2020-03-03 22:41         ` Sean Christopherson
2020-02-01 18:51 ` [PATCH 20/61] KVM: x86: Calculate the supported xcr0 mask at load time Sean Christopherson
2020-02-13 14:21   ` Xiaoyao Li
2020-02-01 18:51 ` [PATCH 21/61] KVM: x86: Use supported_xcr0 to detect MPX support Sean Christopherson
2020-02-13 14:25   ` Xiaoyao Li
2020-02-21 15:32   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 22/61] KVM: x86: Make kvm_mpx_supported() an inline function Sean Christopherson
2020-02-13 14:26   ` Xiaoyao Li
2020-02-21 15:33   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 23/61] KVM: x86: Clear output regs for CPUID 0x14 if PT isn't exposed to guest Sean Christopherson
2020-02-21 15:36   ` Vitaly Kuznetsov [this message]
2020-02-01 18:51 ` [PATCH 24/61] KVM: x86: Drop explicit @func param from ->set_supported_cpuid() Sean Christopherson
2020-02-21 15:39   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 25/61] KVM: x86: Use u32 for holding CPUID register value in helpers Sean Christopherson
2020-02-21 15:43   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 26/61] KVM: x86: Introduce cpuid_entry_{get,has}() accessors Sean Christopherson
2020-02-14  9:44   ` Xiaoyao Li
2020-02-14 17:09     ` Sean Christopherson
2020-02-21 15:57   ` Vitaly Kuznetsov
2020-02-21 16:29     ` Sean Christopherson
2020-02-01 18:51 ` [PATCH 27/61] KVM: x86: Introduce cpuid_entry_{change,set,clear}() mutators Sean Christopherson
     [not found]   ` <87ftf0p0d0.fsf@vitty.brq.redhat.com>
2020-02-24 22:42     ` Sean Christopherson
2020-02-01 18:51 ` [PATCH 28/61] KVM: x86: Refactor cpuid_mask() to auto-retrieve the register Sean Christopherson
2020-02-24 13:49   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 29/61] KVM: x86: Add Kconfig-controlled auditing of reverse CPUID lookups Sean Christopherson
2020-02-24 13:54   ` Vitaly Kuznetsov
2020-02-24 22:46     ` Sean Christopherson
2020-02-25 15:02       ` Paolo Bonzini
2020-02-25 15:00     ` Paolo Bonzini
2020-02-01 18:51 ` [PATCH 30/61] KVM: x86: Handle MPX CPUID adjustment in VMX code Sean Christopherson
2020-02-13 13:51   ` Xiaoyao Li
2020-02-13 17:37     ` Sean Christopherson
2020-02-24 15:14   ` Vitaly Kuznetsov
2020-02-24 15:45     ` Sean Christopherson
2020-02-01 18:51 ` [PATCH 31/61] KVM: x86: Handle INVPCID " Sean Christopherson
2020-02-24 15:19   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 32/61] KVM: x86: Handle UMIP emulation " Sean Christopherson
2020-02-24 15:21   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 33/61] KVM: x86: Handle PKU " Sean Christopherson
2020-02-24 15:24   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 34/61] KVM: x86: Handle RDTSCP " Sean Christopherson
2020-02-24 15:28   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 35/61] KVM: x86: Handle Intel PT " Sean Christopherson
2020-02-24 15:30   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 36/61] KVM: x86: Handle GBPAGE CPUID adjustment for EPT " Sean Christopherson
2020-02-24 15:34   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 37/61] KVM: x86: Refactor handling of XSAVES CPUID adjustment Sean Christopherson
2020-02-24 15:39   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 38/61] KVM: x86: Introduce kvm_cpu_caps to replace runtime CPUID masking Sean Christopherson
2020-02-24 16:32   ` Vitaly Kuznetsov
2020-02-24 22:57     ` Sean Christopherson
2020-02-24 23:20       ` Vitaly Kuznetsov
2020-02-24 23:25         ` Sean Christopherson
2020-02-01 18:51 ` [PATCH 39/61] KVM: SVM: Convert feature updates from CPUID to KVM cpu caps Sean Christopherson
2020-02-24 21:33   ` Vitaly Kuznetsov
2020-02-25 15:10   ` Paolo Bonzini
2020-02-28  0:28     ` Sean Christopherson
2020-02-28  0:36       ` Sean Christopherson
2020-02-28  7:03         ` Paolo Bonzini
2020-02-28 15:09           ` Sean Christopherson
2020-02-01 18:51 ` [PATCH 40/61] KVM: VMX: " Sean Christopherson
2020-02-24 21:40   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 41/61] KVM: x86: Move XSAVES CPUID adjust to VMX's KVM cpu cap update Sean Christopherson
2020-02-24 21:43   ` Vitaly Kuznetsov
2020-02-01 18:51 ` [PATCH 42/61] KVM: x86: Add a helper to check kernel support when setting cpu cap Sean Christopherson
2020-02-24 21:47   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 43/61] KVM: x86: Use KVM cpu caps to mark CR4.LA57 as not-reserved Sean Christopherson
2020-02-24 22:08   ` Vitaly Kuznetsov
2020-02-24 23:23     ` Sean Christopherson
2020-02-25 15:12     ` Paolo Bonzini
2020-02-25 15:19       ` David Laight
2020-02-25 21:22       ` Sean Christopherson
2020-02-26 11:35         ` Paolo Bonzini
2020-02-01 18:52 ` [PATCH 44/61] KVM: x86: Use KVM cpu caps to track UMIP emulation Sean Christopherson
2020-02-24 22:13   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 45/61] KVM: x86: Fold CPUID 0x7 masking back into __do_cpuid_func() Sean Christopherson
2020-02-24 22:21   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 46/61] KVM: x86: Remove the unnecessary loop on CPUID 0x7 sub-leafs Sean Christopherson
2020-02-24 22:25   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 47/61] KVM: x86: Squash CPUID 0x2.0 insanity for modern CPUs Sean Christopherson
2020-02-24 22:35   ` Vitaly Kuznetsov
2020-02-25 15:17   ` Paolo Bonzini
2020-02-01 18:52 ` [PATCH 48/61] KVM: x86: Do host CPUID at load time to mask KVM cpu caps Sean Christopherson
     [not found]   ` <87o8tnmwni.fsf@vitty.brq.redhat.com>
2020-02-24 23:31     ` Sean Christopherson
2020-02-25 13:53       ` Vitaly Kuznetsov
2020-02-25 15:18   ` Paolo Bonzini
2020-02-25 21:08     ` Sean Christopherson
2020-02-29 18:38       ` Sean Christopherson
2020-02-01 18:52 ` [PATCH 49/61] KVM: x86: Override host CPUID results with kvm_cpu_caps Sean Christopherson
2020-02-24 22:57   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 50/61] KVM: x86: Set emulated/transmuted feature bits via kvm_cpu_caps Sean Christopherson
2020-02-25 13:59   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 51/61] KVM: x86: Use kvm_cpu_caps to detect Intel PT support Sean Christopherson
2020-02-25 14:06   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 52/61] KVM: x86: Use KVM cpu caps to detect MSR_TSC_AUX virt support Sean Christopherson
2020-02-25 14:08   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 53/61] KVM: VMX: Directly use VMX capabilities helper to detect RDTSCP support Sean Christopherson
2020-02-25 14:10   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 54/61] KVM: x86: Check for Intel PT MSR virtualization using KVM cpu caps Sean Christopherson
2020-02-25 14:11   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 55/61] KVM: VMX: Directly query Intel PT mode when refreshing PMUs Sean Christopherson
2020-02-25 14:16   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 56/61] KVM: SVM: Refactor logging of NPT enabled/disabled Sean Christopherson
2020-02-25 14:21   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 57/61] KVM: x86/mmu: Merge kvm_{enable,disable}_tdp() into a common function Sean Christopherson
2020-02-25 14:27   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 58/61] KVM: x86/mmu: Configure max page level during hardware setup Sean Christopherson
2020-02-25 14:43   ` Vitaly Kuznetsov
2020-02-25 21:01     ` Sean Christopherson
2020-02-26 14:55       ` Vitaly Kuznetsov
2020-02-26 15:56         ` Sean Christopherson
2020-02-01 18:52 ` [PATCH 59/61] KVM: x86: Don't propagate MMU lpage support to memslot.disallow_lpage Sean Christopherson
2020-02-25 14:55   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 60/61] KVM: Drop largepages_enabled and its accessor/mutator Sean Christopherson
2020-02-25 14:56   ` Vitaly Kuznetsov
2020-02-01 18:52 ` [PATCH 61/61] KVM: x86: Move VMX's host_efer to common x86 code Sean Christopherson
2020-02-25 15:02   ` Vitaly Kuznetsov
     [not found] ` <87wo8ak84x.fsf@vitty.brq.redhat.com>
2020-02-25 15:25   ` [PATCH 00/61] KVM: x86: Introduce KVM cpu caps Paolo Bonzini
2020-02-28  1:37     ` Sean Christopherson
2020-02-28  7:04       ` Paolo Bonzini
2020-02-29 18:32   ` Sean Christopherson
2020-03-02  9:03     ` Vitaly Kuznetsov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87eeuoq7fj.fsf@vitty.brq.redhat.com \
    --to=vkuznets@redhat.com \
    --cc=jmattson@google.com \
    --cc=joro@8bytes.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=sean.j.christopherson@intel.com \
    --cc=wanpengli@tencent.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).