From: "Kuppuswamy, Sathyanarayanan" <sathyanarayanan.kuppuswamy@linux.intel.com> To: 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 Subject: Re: [PATCH v5 07/12] x86/traps: Add #VE support for TDX guest Date: Tue, 24 Aug 2021 10:32:13 -0700 [thread overview] Message-ID: <99c5f6e9-a747-1a4a-d0f4-95b8b28e0d02@linux.intel.com> (raw) In-Reply-To: <YSTHMAUA1LjjOQPe@zn.tnic> On 8/24/21 3:17 AM, Borislav Petkov wrote: > On Wed, Aug 04, 2021 at 11:13:24AM -0700, Kuppuswamy Sathyanarayanan wrote: >> If a guest kernel action which would normally cause a #VE occurs in the >> interrupt-disabled region before TDGETVEINFO, a #DF is delivered to the >> guest which will result in an oops (and should eventually be a panic, as >> we would like to set panic_on_oops to 1 for TDX guests). > > Who's "we"? > > Please use passive voice in your commit message and comments: no "we" > or "I", etc. Personal pronouns are ambiguous in text, especially with > so many parties/companies/etc developing the kernel so let's avoid them. > > Audit all your patchsets pls. Sorry. I will fix this in next version. > >> Add basic infrastructure to handle any #VE which occurs in the kernel or >> userspace. Later patches will add handling for specific #VE scenarios. >> >> Convert unhandled #VE's (everything, until later in this series) so that >> they appear just like a #GP by calling ve_raise_fault() directly. >> ve_raise_fault() is similar to #GP handler and is responsible for >> sending SIGSEGV to userspace and cpu die and notifying debuggers and > > In all your text: > > s/cpu/CPU/g > > Audit all your patchsets pls. Yes. I will fix this in next version. > >> @@ -53,6 +67,11 @@ u64 __tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9, >> u64 __tdx_hypercall(u64 type, u64 fn, u64 r12, u64 r13, u64 r14, >> u64 r15, struct tdx_hypercall_output *out); >> >> +unsigned long tdg_get_ve_info(struct ve_info *ve); >> + >> +int tdg_handle_virtualization_exception(struct pt_regs *regs, > > There's that "tdg" prefix again. Please fix all your patchsets. Mainly chose it avoid future name conflicts with KVM (tdx) calls. But if you don't like "tdg", I can change it back to "tdx" and resolve the naming issues when it occurs. >> static struct { >> unsigned int gpa_width; >> @@ -75,6 +76,41 @@ static void tdg_get_info(void) >> td_info.attributes = out.rdx; >> } >> >> +unsigned long tdg_get_ve_info(struct ve_info *ve) >> +{ >> + u64 ret; >> + struct tdx_module_output out = {0}; > > The tip-tree preferred ordering of variable declarations at the > beginning of a function is reverse fir tree order:: > > struct long_struct_name *descriptive_name; > unsigned long foo, bar; > unsigned int tmp; > int ret; > > The above is faster to parse than the reverse ordering:: > > int ret; > unsigned int tmp; > unsigned long foo, bar; > struct long_struct_name *descriptive_name; > > And even more so than random ordering:: > > unsigned long foo, bar; > int ret; > struct long_struct_name *descriptive_name; > unsigned int tmp; Yes. I will fix this in next version. >> +int tdg_handle_virtualization_exception(struct pt_regs *regs, >> + struct ve_info *ve) >> +{ >> + /* >> + * TODO: Add handler support for various #VE exit >> + * reasons. It will be added by other patches in >> + * the series. >> + */ > > That comment needs to go. Ok. I will remove it. >> +#ifdef CONFIG_INTEL_TDX_GUEST >> +#define VEFSTR "VE fault" >> +static void ve_raise_fault(struct pt_regs *regs, long error_code) >> +{ >> + struct task_struct *tsk = current; >> + >> + if (user_mode(regs)) { >> + tsk->thread.error_code = error_code; >> + tsk->thread.trap_nr = X86_TRAP_VE; >> + >> + /* >> + * Not fixing up VDSO exceptions similar to #GP handler >> + * because we don't expect the VDSO to trigger #VE. >> + */ >> + show_signal(tsk, SIGSEGV, "", VEFSTR, regs, error_code); >> + force_sig(SIGSEGV); >> + return; >> + } >> + >> + if (fixup_exception(regs, X86_TRAP_VE, error_code, 0)) > > There are exception table entries which can trigger a #VE? It is required to handle #VE exceptions raised by unhandled MSR read/writes. > >> + return; >> + >> + tsk->thread.error_code = error_code; >> + tsk->thread.trap_nr = X86_TRAP_VE; >> + >> + /* >> + * To be potentially processing a kprobe fault and to trust the result >> + * from kprobe_running(), we have to be non-preemptible. >> + */ >> + if (!preemptible() && >> + kprobe_running() && >> + kprobe_fault_handler(regs, X86_TRAP_VE)) >> + return; >> + >> + notify_die(DIE_GPF, VEFSTR, regs, error_code, X86_TRAP_VE, SIGSEGV); > > Other handlers check that retval. Ok. I can check it. But there is only one statement after this call. So it may not be very helpful. > -- Sathyanarayanan Kuppuswamy Linux Kernel Developer
next prev parent reply other threads:[~2021-08-24 17:43 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 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 [this message] 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
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=99c5f6e9-a747-1a4a-d0f4-95b8b28e0d02@linux.intel.com \ --to=sathyanarayanan.kuppuswamy@linux.intel.com \ --cc=ak@linux.intel.com \ --cc=bp@alien8.de \ --cc=dan.j.williams@intel.com \ --cc=dave.hansen@intel.com \ --cc=hpa@zytor.com \ --cc=kirill.shutemov@linux.intel.com \ --cc=knsathya@kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=luto@kernel.org \ --cc=mingo@redhat.com \ --cc=peterz@infradead.org \ --cc=seanjc@google.com \ --cc=tglx@linutronix.de \ --cc=tony.luck@intel.com \ --cc=x86@kernel.org \ --subject='Re: [PATCH v5 07/12] x86/traps: Add #VE support for TDX guest' \ /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
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).