lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Sun, 17 Oct 2021 13:35:23 -0700 From: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@...ux.intel.com> To: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, x86@...nel.org, Paolo Bonzini <pbonzini@...hat.com>, David Hildenbrand <david@...hat.com>, Andrea Arcangeli <aarcange@...hat.com>, Josh Poimboeuf <jpoimboe@...hat.com>, "H . Peter Anvin" <hpa@...or.com>, thomas.lendacky@....com Cc: Dave Hansen <dave.hansen@...el.com>, Tony Luck <tony.luck@...el.com>, Dan Williams <dan.j.williams@...el.com>, Andi Kleen <ak@...ux.intel.com>, Kirill Shutemov <kirill.shutemov@...ux.intel.com>, Sean Christopherson <seanjc@...gle.com>, Kuppuswamy Sathyanarayanan <knsathya@...nel.org>, linux-kernel@...r.kernel.org Subject: Re: [PATCH v7 05/10] x86/tdx: Handle port I/O 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
Powered by blists - more mailing lists