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From: "Kuppuswamy, Sathyanarayanan"  <sathyanarayanan.kuppuswamy@linux.intel.com>
To: Juergen Gross <jgross@suse.com>, Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Andy Lutomirski <luto@kernel.org>, Peter H Anvin <hpa@zytor.com>,
	Dave Hansen <dave.hansen@intel.com>,
	Tony Luck <tony.luck@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Kirill Shutemov <kirill.shutemov@linux.intel.com>,
	Sean Christopherson <seanjc@google.com>,
	Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
	x86@kernel.org, linux-kernel@vger.kernel.org,
	Deep Shah <sdeep@vmware.com>,
	"VMware, Inc." <pv-drivers@vmware.com>
Subject: Re: [PATCH v5 01/12] x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT
Date: Tue, 17 Aug 2021 06:16:23 -0700	[thread overview]
Message-ID: <fd603d12-1897-1f5f-17fa-b5ac643bc334@linux.intel.com> (raw)
In-Reply-To: <057170db-9382-eb40-7bcb-4ec1de4aae62@suse.com>



On 8/17/21 5:50 AM, Juergen Gross wrote:
> On 12.08.21 09:18, Borislav Petkov wrote:
>> On Wed, Aug 04, 2021 at 11:13:18AM -0700, Kuppuswamy Sathyanarayanan wrote:
>>> From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
>>>
>>> CONFIG_PARAVIRT_XXL is mainly defined/used by XEN PV guests. For
>>> other VM guest types, features supported under CONFIG_PARAVIRT
>>> are self sufficient. CONFIG_PARAVIRT mainly provides support for
>>> TLB flush operations and time related operations.
>>>
>>> For TDX guest as well, paravirt calls under CONFIG_PARVIRT meets
>>> most of its requirement except the need of HLT and SAFE_HLT
>>> paravirt calls, which is currently defined under
>>> COFNIG_PARAVIRT_XXL.
>>>
>>> Since enabling CONFIG_PARAVIRT_XXL is too bloated for TDX guest
>>> like platforms, move HLT and SAFE_HLT paravirt calls under
>>> CONFIG_PARAVIRT.
>>>
>>> Moving HLT and SAFE_HLT paravirt calls are not fatal and should not
>>> break any functionality for current users of CONFIG_PARAVIRT.
>>>
>>> Co-developed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
>>> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
>>> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
>>> Reviewed-by: Andi Kleen <ak@linux.intel.com>
>>> Reviewed-by: Tony Luck <tony.luck@intel.com>
>>> ---
>>
>> You need to do this before sending your patches:
>>
>> ./scripts/get_maintainer.pl /tmp/tdx.01
>> Thomas Gleixner <tglx@linutronix.de> (maintainer:X86 ARCHITECTURE (32-BIT AND 
>> 64-BIT),commit_signer:1/6=17%)
>> Ingo Molnar <mingo@redhat.com> (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT))
>> Borislav Petkov <bp@alien8.de> (maintainer:X86 ARCHITECTURE (32-BIT AND 
>> 64-BIT),commit_signer:6/6=100%)
>> x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT))
>> "H. Peter Anvin" <hpa@zytor.com> (reviewer:X86 ARCHITECTURE (32-BIT AND 64-BIT))
>> Juergen Gross <jgross@suse.com> (supporter:PARAVIRT_OPS 
>> INTERFACE,commit_signer:5/6=83%,authored:5/6=83%,added_lines:15/16=94%,removed_lines:38/39=97%)
>> Deep Shah <sdeep@vmware.com> (supporter:PARAVIRT_OPS INTERFACE)
>> "VMware, Inc." <pv-drivers@vmware.com> (supporter:PARAVIRT_OPS INTERFACE)
>> ...
>>
>> and CC also the supporters - I'm pretty sure at least Juergen would like
>> to be kept up-to-date on pv changes. I'll CC him and the others now and
>> leave in the whole diff but make sure you do that in the future please.
>>
>>>   arch/x86/include/asm/irqflags.h       | 40 +++++++++++++++------------
>>>   arch/x86/include/asm/paravirt.h       | 20 +++++++-------
>>>   arch/x86/include/asm/paravirt_types.h |  3 +-
>>>   arch/x86/kernel/paravirt.c            |  4 ++-
>>>   4 files changed, 36 insertions(+), 31 deletions(-)
>>>
>>> diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
>>> index c5ce9845c999..f3bb33b1715d 100644
>>> --- a/arch/x86/include/asm/irqflags.h
>>> +++ b/arch/x86/include/asm/irqflags.h
>>> @@ -59,6 +59,28 @@ static inline __cpuidle void native_halt(void)
>>>   #endif
>>> +#ifndef CONFIG_PARAVIRT
>>> +#ifndef __ASSEMBLY__
>>> +/*
>>> + * Used in the idle loop; sti takes one instruction cycle
>>> + * to complete:
>>> + */
>>> +static inline __cpuidle void arch_safe_halt(void)
>>> +{
>>> +    native_safe_halt();
>>> +}
>>> +
>>> +/*
>>> + * Used when interrupts are already enabled or to
>>> + * shutdown the processor:
>>> + */
>>> +static inline __cpuidle void halt(void)
>>> +{
>>> +    native_halt();
>>> +}
>>> +#endif /* __ASSEMBLY__ */
>>> +#endif /* CONFIG_PARAVIRT */
>>> +
>>>   #ifdef CONFIG_PARAVIRT_XXL
>>>   #include <asm/paravirt.h>
> 
> Did you test this with CONFIG_PARAVIRT enabled and CONFIG_PARAVIRT_XXL
> disabled?
> 
> I'm asking because in this case I don't see where halt() and
> arch_safe_halt() would be defined in case someone is including
> asm/irqflags.h and not asm/paravirt.h.

We have tested both cases and did not hit any issues.

1. CONFIG_PARAVIRT=y and  CONFIG_PARAVIRT_XXL=y
2. CONFIG_PARAVIRT=y and  CONFIG_PARAVIRT_XXL=n


>>> diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
>>> index 04cafc057bed..124e0f6c5d1c 100644
>>> --- a/arch/x86/kernel/paravirt.c
>>> +++ b/arch/x86/kernel/paravirt.c
>>> @@ -283,9 +283,11 @@ struct paravirt_patch_template pv_ops = {
>>>       .irq.save_fl        = __PV_IS_CALLEE_SAVE(native_save_fl),
>>>       .irq.irq_disable    = __PV_IS_CALLEE_SAVE(native_irq_disable),
>>>       .irq.irq_enable        = __PV_IS_CALLEE_SAVE(native_irq_enable),
>>> +#endif /* CONFIG_PARAVIRT_XXL */
>>> +
>>> +    /* Irq HLT ops. */
>>
>> What's that comment for?
> 
> I agree, please drop it.

Yes. I will drop it.

> 
> 
> Juergen

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer

  reply	other threads:[~2021-08-17 13:16 UTC|newest]

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-04 18:13 [PATCH v5 00/12] Add TDX Guest Support (Initial support) Kuppuswamy Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 01/12] x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT Kuppuswamy Sathyanarayanan
2021-08-12  7:18   ` Borislav Petkov
2021-08-12 17:17     ` Kuppuswamy, Sathyanarayanan
2021-08-17 12:50     ` Juergen Gross
2021-08-17 13:16       ` Kuppuswamy, Sathyanarayanan [this message]
2021-08-17 13:28         ` Juergen Gross
2021-08-17 13:39           ` Kuppuswamy, Sathyanarayanan
2021-08-17 13:47             ` Juergen Gross
2021-08-17 13:50               ` Kuppuswamy, Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 02/12] x86/tdx: Introduce INTEL_TDX_GUEST config option Kuppuswamy Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 03/12] x86/cpufeatures: Add TDX Guest CPU feature Kuppuswamy Sathyanarayanan
2021-08-12  7:39   ` Borislav Petkov
2021-08-04 18:13 ` [PATCH v5 04/12] x86/tdx: Add protected guest support for TDX guest Kuppuswamy Sathyanarayanan
2021-08-04 21:59   ` Sean Christopherson
2021-08-04 22:03     ` Dave Hansen
2021-08-04 22:26       ` Kuppuswamy, Sathyanarayanan
2021-08-04 22:42         ` Sean Christopherson
2021-08-04 23:00           ` Kuppuswamy, Sathyanarayanan
2021-08-12  7:53             ` Borislav Petkov
2021-08-12 17:18               ` Kuppuswamy, Sathyanarayanan
2021-08-20 14:28                 ` Borislav Petkov
2021-08-20 16:42                   ` Kuppuswamy, Sathyanarayanan
2021-08-20 16:59                     ` Borislav Petkov
2021-08-20 17:11                       ` Kuppuswamy, Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 05/12] x86/tdx: Add __tdx_module_call() and __tdx_hypercall() helper functions Kuppuswamy Sathyanarayanan
2021-08-20 15:16   ` Borislav Petkov
2021-08-04 18:13 ` [PATCH v5 06/12] x86/tdx: Get TD execution environment information via TDINFO Kuppuswamy Sathyanarayanan
2021-08-04 22:38   ` Sean Christopherson
2021-08-20 17:13   ` Borislav Petkov
2021-08-20 17:31     ` Kuppuswamy, Sathyanarayanan
2021-08-20 17:35       ` Borislav Petkov
2021-08-20 18:29         ` Kuppuswamy, Sathyanarayanan
2021-08-20 18:58           ` Andi Kleen
2021-08-20 19:01             ` Kuppuswamy, Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 07/12] x86/traps: Add #VE support for TDX guest Kuppuswamy Sathyanarayanan
2021-08-24 10:17   ` Borislav Petkov
2021-08-24 17:32     ` Kuppuswamy, Sathyanarayanan
2021-08-24 17:36       ` Dave Hansen
2021-08-24 17:46       ` Borislav Petkov
2021-09-02 15:24         ` Kuppuswamy, Sathyanarayanan
2021-09-03 10:17           ` Borislav Petkov
2021-08-04 18:13 ` [PATCH v5 08/12] x86/tdx: Add HLT " Kuppuswamy Sathyanarayanan
2021-08-24 16:10   ` Borislav Petkov
2021-08-24 17:06     ` Sean Christopherson
2021-08-24 17:25       ` Andi Kleen
2021-08-24 17:27       ` Borislav Petkov
2021-08-24 17:47         ` Sean Christopherson
2021-08-24 17:50           ` Borislav Petkov
2021-08-31 20:49         ` Kuppuswamy, Sathyanarayanan
2021-09-01  7:42           ` Borislav Petkov
2021-08-24 18:18       ` Kuppuswamy, Sathyanarayanan
2021-08-24 18:28         ` Andi Kleen
2021-08-24 17:35     ` Kuppuswamy, Sathyanarayanan
2021-08-24 17:48       ` Borislav Petkov
2021-08-04 18:13 ` [PATCH v5 09/12] x86/tdx: Wire up KVM hypercalls Kuppuswamy Sathyanarayanan
2021-08-24 16:34   ` Borislav Petkov
2021-08-24 18:11     ` Kuppuswamy, Sathyanarayanan
2021-08-24 18:29       ` Borislav Petkov
2021-08-24 19:11         ` Kuppuswamy, Sathyanarayanan
2021-08-24 19:39           ` Borislav Petkov
2021-08-04 18:13 ` [PATCH v5 10/12] x86/tdx: Add MSR support for TDX guest Kuppuswamy Sathyanarayanan
2021-08-24 16:55   ` Borislav Petkov
2021-08-24 18:12     ` Kuppuswamy, Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 11/12] x86/tdx: Don't write CSTAR MSR on Intel Kuppuswamy Sathyanarayanan
2021-08-04 18:31   ` Sean Christopherson
2021-08-04 21:03     ` Kuppuswamy, Sathyanarayanan
2021-08-04 21:44       ` Sean Christopherson
2021-08-04 21:48       ` Dave Hansen
2021-08-04 22:23         ` Kuppuswamy, Sathyanarayanan
2021-08-04 18:13 ` [PATCH v5 12/12] x86/tdx: Handle CPUID via #VE Kuppuswamy Sathyanarayanan
2021-08-24 17:48   ` Borislav Petkov

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