All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Joerg Roedel <joro@8bytes.org>
Cc: x86@kernel.org, Joerg Roedel <jroedel@suse.de>,
	hpa@zytor.com, Andy Lutomirski <luto@kernel.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Jiri Slaby <jslaby@suse.cz>,
	Dan Williams <dan.j.williams@intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Juergen Gross <jgross@suse.com>,
	Kees Cook <keescook@chromium.org>,
	David Rientjes <rientjes@google.com>,
	Cfir Cohen <cfir@google.com>, Erdem Aktas <erdemaktas@google.com>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Mike Stunes <mstunes@vmware.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Martin Radev <martin.b.radev@gmail.com>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	virtualization@lists.linux-foundation.org
Subject: Re: [PATCH v4 00/75] x86: SEV-ES Guest Support
Date: Wed, 15 Jul 2020 11:24:56 +0200	[thread overview]
Message-ID: <20200715092456.GE10769@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200714120917.11253-1-joro@8bytes.org>

On Tue, Jul 14, 2020 at 02:08:02PM +0200, Joerg Roedel wrote:
> The #VC entry code now tries to pretend that the #VC handler does not
> use an IST stack by switching to the task stack if entered from
> user-mode or the SYSCALL entry path. When it is entered from
> kernel-mode it is doing its best to switch back to the interrupted
> stack. This is only possible if it is entered from a known and safe
> kernel stack (e.g. not the entry stack). If the previous stack is not
> safe to use the #VC handler switches to a fall-back stack and calls a
> special handler function which, as of now, just panics the system. For
> now this is safe as #VC exceptions only happen at know places which
> use a safe stack.
> 
> The use of the fall-back stack is necessary so that the special
> handler function can safely raise nested #VC exceptions, for
> example to print a panic message.

Can we get some more words -- preferably in actual code comments, on
when exactly #VC happens?

Because the only thing I remember is that #VC could happen on any memop,
but I also have vague memories of that being a later extention.

  parent reply	other threads:[~2020-07-15  9:25 UTC|newest]

Thread overview: 165+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-14 12:08 [PATCH v4 00/75] x86: SEV-ES Guest Support Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 01/75] KVM: SVM: Add GHCB definitions Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 02/75] KVM: SVM: Add GHCB Accessor functions Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 03/75] KVM: SVM: Use __packed shorthand Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 04/75] x86/cpufeatures: Add SEV-ES CPU feature Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 05/75] x86/traps: Move pf error codes to <asm/trap_pf.h> Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 06/75] x86/insn: Make inat-tables.c suitable for pre-decompression code Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-17 13:58   ` Masami Hiramatsu
2020-07-14 12:08 ` [PATCH v4 07/75] x86/umip: Factor out instruction fetch Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 08/75] x86/umip: Factor out instruction decoding Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 09/75] x86/insn: Add insn_get_modrm_reg_off() Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 10/75] x86/insn: Add insn_has_rep_prefix() helper Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-17 14:06   ` Masami Hiramatsu
2020-07-14 12:08 ` [PATCH v4 11/75] x86/boot/compressed/64: Disable red-zone usage Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 12/75] x86/boot/compressed/64: Add IDT Infrastructure Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 13/75] x86/boot/compressed/64: Rename kaslr_64.c to ident_map_64.c Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-15  1:23   ` Kees Cook
2020-07-15  1:23     ` Kees Cook
2020-07-14 12:08 ` [PATCH v4 14/75] x86/boot/compressed/64: Add page-fault handler Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-15  1:24   ` Kees Cook
2020-07-14 12:08 ` [PATCH v4 15/75] x86/boot/compressed/64: Always switch to own page-table Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-15  1:23   ` Kees Cook
2020-07-14 12:08 ` [PATCH v4 16/75] x86/boot/compressed/64: Don't pre-map memory in KASLR code Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-15  1:24   ` Kees Cook
2020-07-14 12:08 ` [PATCH v4 17/75] x86/boot/compressed/64: Change add_identity_map() to take start and end Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-15  1:24   ` Kees Cook
2020-07-14 12:08 ` [PATCH v4 18/75] x86/boot/compressed/64: Add stage1 #VC handler Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 19/75] x86/boot/compressed/64: Call set_sev_encryption_mask earlier Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 20/75] x86/boot/compressed/64: Check return value of kernel_ident_mapping_init() Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 21/75] x86/boot/compressed/64: Add set_page_en/decrypted() helpers Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 22/75] x86/boot/compressed/64: Setup GHCB Based VC Exception handler Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 23/75] x86/boot/compressed/64: Unmap GHCB page before booting the kernel Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 24/75] x86/sev-es: Add support for handling IOIO exceptions Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 25/75] x86/fpu: Move xgetbv()/xsetbv() into separate header Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 26/75] x86/sev-es: Add CPUID handling to #VC handler Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 27/75] x86/idt: Move IDT to data segment Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-15  1:25   ` Kees Cook
2020-07-14 12:08 ` [PATCH v4 28/75] x86/idt: Split idt_data setup out of set_intr_gate() Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-15  1:26   ` Kees Cook
2020-07-14 12:08 ` [PATCH v4 29/75] x86/idt: Move two function from k/idt.c to i/a/desc.h Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-15  1:29   ` Kees Cook
2020-07-14 12:08 ` [PATCH v4 30/75] x86/head/64: Install boot GDT Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 31/75] x86/head/64: Reload GDT after switch to virtual addresses Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 32/75] x86/head/64: Load segment registers earlier Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 33/75] x86/head/64: Switch to initial stack earlier Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 34/75] x86/head/64: Build k/head64.c with -fno-stack-protector Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-15  1:34   ` Kees Cook
2020-07-15  1:34     ` Kees Cook
2020-07-15 16:34     ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 35/75] x86/head/64: Load IDT earlier Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 36/75] x86/head/64: Move early exception dispatch to C code Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 37/75] x86/sev-es: Add SEV-ES Feature Detection Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 38/75] x86/sev-es: Print SEV-ES info into kernel log Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 39/75] x86/sev-es: Compile early handler code into kernel image Joerg Roedel
2020-07-14 12:08   ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 40/75] x86/sev-es: Setup early #VC handler Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 41/75] x86/sev-es: Setup GHCB based boot " Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 42/75] x86/sev-es: Setup per-cpu GHCBs for the runtime handler Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 43/75] x86/sev-es: Allocate and Map stacks for #VC handler Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 44/75] x86/sev-es: Allocate and setup IST entry for #VC Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 45/75] x86/sev-es: Adjust #VC IST Stack on entering NMI handler Joerg Roedel
2020-07-15  9:47   ` Peter Zijlstra
2020-07-15 10:26     ` Joerg Roedel
2020-07-15 10:56       ` Peter Zijlstra
2020-07-15 10:56         ` Peter Zijlstra
2020-07-14 12:08 ` [PATCH v4 46/75] x86/dumpstack/64: Add noinstr version of get_stack_info() Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 47/75] x86/entry/64: Add entry code for #VC handler Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 48/75] x86/sev-es: Add Runtime #VC Exception Handler Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 49/75] x86/sev-es: Wire up existing #VC exit-code handlers Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 50/75] x86/sev-es: Handle instruction fetches from user-space Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 51/75] x86/sev-es: Handle MMIO events Joerg Roedel
2020-07-21 21:01   ` Mike Stunes
2020-07-21 21:01     ` Mike Stunes
2020-07-22  7:55     ` Joerg Roedel
2020-07-22  7:55       ` Joerg Roedel
2020-07-22  8:05     ` Joerg Roedel
2020-07-22  8:05       ` Joerg Roedel
2020-07-22 22:53       ` Mike Stunes
2020-07-22 22:53         ` Mike Stunes
2020-07-23  7:21         ` Joerg Roedel
2020-07-23  7:21           ` Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 52/75] x86/sev-es: Handle MMIO String Instructions Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 53/75] x86/sev-es: Handle MSR events Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 54/75] x86/sev-es: Handle DR7 read/write events Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 55/75] x86/sev-es: Handle WBINVD Events Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 56/75] x86/sev-es: Handle RDTSC(P) Events Joerg Roedel
2020-07-14 12:08 ` [PATCH v4 57/75] x86/sev-es: Handle RDPMC Events Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 58/75] x86/sev-es: Handle INVD Events Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 59/75] x86/sev-es: Handle MONITOR/MONITORX Events Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 60/75] x86/sev-es: Handle MWAIT/MWAITX Events Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 61/75] x86/sev-es: Handle VMMCALL Events Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 62/75] x86/sev-es: Handle #AC Events Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 63/75] x86/sev-es: Handle #DB Events Joerg Roedel
2020-07-15  8:47   ` Peter Zijlstra
2020-07-15  8:47     ` Peter Zijlstra
2020-07-15  9:13     ` Joerg Roedel
2020-07-15  9:51       ` Peter Zijlstra
2020-07-15  9:51         ` Peter Zijlstra
2020-07-15 10:08         ` Joerg Roedel
2020-07-15 10:13           ` Peter Zijlstra
2020-07-15 10:13             ` Peter Zijlstra
2020-07-15 10:31             ` Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 64/75] x86/paravirt: Allow hypervisor specific VMMCALL handling under SEV-ES Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 65/75] x86/kvm: Add KVM " Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 66/75] x86/vmware: Add VMware specific handling for VMMCALL " Joerg Roedel
2020-07-14 12:09   ` Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 67/75] x86/realmode: Add SEV-ES specific trampoline entry point Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 68/75] x86/realmode: Setup AP jump table Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 69/75] x86/head/64: Setup TSS early for secondary CPUs Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 70/75] x86/head/64: Don't call verify_cpu() on starting APs Joerg Roedel
2020-07-15  1:40   ` Kees Cook
2020-07-15  9:26     ` Joerg Roedel
2020-07-15 15:26       ` Kees Cook
2020-07-15 15:48         ` Joerg Roedel
2020-07-15 19:49           ` Kees Cook
2020-07-20 15:29             ` Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 71/75] x86/head/64: Rename start_cpu0 Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 72/75] x86/sev-es: Support CPU offline/online Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 73/75] x86/sev-es: Handle NMI State Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 74/75] x86/efi: Add GHCB mappings when SEV-ES is active Joerg Roedel
2020-07-14 12:09 ` [PATCH v4 75/75] x86/sev-es: Check required CPU features for SEV-ES Joerg Roedel
2020-07-14 18:53   ` kernel test robot
2020-07-15  9:24 ` Peter Zijlstra [this message]
2020-07-15  9:34   ` [PATCH v4 00/75] x86: SEV-ES Guest Support Joerg Roedel
2020-07-15  9:55     ` Peter Zijlstra
2020-07-15  9:55       ` Peter Zijlstra
2020-07-15 10:10       ` Joerg Roedel
2020-07-21  1:09         ` Erdem Aktas
2020-07-21 12:49           ` Joerg Roedel
2020-07-21 12:49             ` Joerg Roedel
2020-07-21 16:48             ` Erdem Aktas
2020-07-22  9:04               ` Joerg Roedel
2020-07-22 16:54                 ` Erdem Aktas
2020-07-22 17:45                   ` Joerg Roedel

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=20200715092456.GE10769@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=cfir@google.com \
    --cc=dan.j.williams@intel.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=erdemaktas@google.com \
    --cc=hpa@zytor.com \
    --cc=jgross@suse.com \
    --cc=joro@8bytes.org \
    --cc=jroedel@suse.de \
    --cc=jslaby@suse.cz \
    --cc=keescook@chromium.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=martin.b.radev@gmail.com \
    --cc=mhiramat@kernel.org \
    --cc=mstunes@vmware.com \
    --cc=rientjes@google.com \
    --cc=sean.j.christopherson@intel.com \
    --cc=thomas.lendacky@amd.com \
    --cc=virtualization@lists.linux-foundation.org \
    --cc=x86@kernel.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.