From: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
David Hildenbrand <david@redhat.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
"H . Peter Anvin" <hpa@zytor.com>,
thomas.lendacky@amd.com
Cc: 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>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 05/10] x86/tdx: Handle port I/O
Date: Sun, 17 Oct 2021 13:35:23 -0700 [thread overview]
Message-ID: <eadc3025-a32d-3641-de83-e5f05728a755@linux.intel.com> (raw)
In-Reply-To: <87v91v2zkk.ffs@tglx>
On 10/17/21 12:58 PM, Thomas Gleixner wrote:
> On Tue, Oct 05 2021 at 13:41, Kuppuswamy Sathyanarayanan wrote:
>> \
>> static inline void outs##bwl(int port, const void *addr, unsigned long count) \
>> { \
>> - if (sev_key_active()) { \
>> + if (sev_key_active() || \
>> + cc_platform_has(CC_ATTR_GUEST_UNROLL_STRING_IO)) { \
> Instead of adding an extra check, can you please replace that
> sev_key_active() with cc_platform_has() completely?
Yes. sev_key_active() can be removed and replaced with
cc_platform_has().
Thomas Lendacky also proposed to introduce as common
static key which can be set by both AMD SEV and TDX code.
@Thomas Lendacky, any comments?
>
>> +/*
>> + * tdx_handle_early_io() cannot be re-used in #VE handler for handling
>> + * I/O because the way of handling string I/O is different between
>> + * normal and early I/O case. Also, once trace support is enabled,
>> + * tdx_handle_io() will be extended to use trace calls which is also
>> + * not valid for early I/O cases.
>> + */
>> +static void tdx_handle_io(struct pt_regs *regs, u32 exit_qual)
>> +{
>> + struct tdx_hypercall_output outh;
>> + int out, size, port, ret;
>> + bool string;
>> + u64 mask;
>> +
>> + string = VE_IS_IO_STRING(exit_qual);
>> +
>> + /* I/O strings ops are unrolled at build time. */
> Fancy. The compiler can evaluate sev_key_active() and
> cc_platform_has() at build time?
It is incorrect. I will fix this in next version. How about following
change?
I/O strings are replaced with in/out instructions. If string is reported,
report it with BUG.
>
> Thanks,
>
> tglx
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
next prev parent reply other threads:[~2021-10-17 20:35 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-05 20:41 [PATCH v7 00/10] Add TDX Guest Support (#VE handler support) Kuppuswamy Sathyanarayanan
2021-10-05 20:41 ` [PATCH v7 01/10] x86/io: Allow to override inX() and outX() implementation Kuppuswamy Sathyanarayanan
2021-10-17 19:27 ` Thomas Gleixner
2021-10-17 20:17 ` Sathyanarayanan Kuppuswamy
2021-10-05 20:41 ` [PATCH v7 02/10] x86/tdx: Add early_is_tdx_guest() interface Kuppuswamy Sathyanarayanan
2021-10-17 19:28 ` Thomas Gleixner
2021-10-05 20:41 ` [PATCH v7 03/10] x86/tdx: Handle port I/O in decompression code Kuppuswamy Sathyanarayanan
2021-10-05 20:41 ` [PATCH v7 04/10] x86/tdx: Handle early IO operations Kuppuswamy Sathyanarayanan
2021-11-05 21:12 ` Sean Christopherson
2021-11-05 23:08 ` Sathyanarayanan Kuppuswamy
2021-10-05 20:41 ` [PATCH v7 05/10] x86/tdx: Handle port I/O Kuppuswamy Sathyanarayanan
2021-10-17 19:58 ` Thomas Gleixner
2021-10-17 20:35 ` Sathyanarayanan Kuppuswamy [this message]
2021-10-18 13:52 ` Tom Lendacky
2021-10-18 18:42 ` Sathyanarayanan Kuppuswamy
2021-11-05 21:23 ` Sean Christopherson
2021-10-05 20:41 ` [PATCH v7 06/10] x86/insn-eval: Introduce insn_get_modrm_reg_ptr() Kuppuswamy Sathyanarayanan
2021-10-05 20:41 ` [PATCH v7 07/10] x86/insn-eval: Introduce insn_decode_mmio() Kuppuswamy Sathyanarayanan
2021-10-05 20:41 ` [PATCH v7 08/10] x86/sev-es: Use insn_decode_mmio() for MMIO implementation Kuppuswamy Sathyanarayanan
2021-10-05 20:41 ` [PATCH v7 09/10] x86/tdx: Handle in-kernel MMIO Kuppuswamy Sathyanarayanan
2021-11-05 22:41 ` Sean Christopherson
2021-10-05 20:41 ` [PATCH v7 10/10] x86/tdx: Handle MWAIT and MONITOR Kuppuswamy Sathyanarayanan
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