From: Dave Hansen <dave.hansen@intel.com>
To: Alexey Gladkov <legion@kernel.org>,
linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Yuan Yao <yuan.yao@intel.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Yuntao Wang <ytcoode@gmail.com>, Kai Huang <kai.huang@intel.com>,
Baoquan He <bhe@redhat.com>, Oleg Nesterov <oleg@redhat.com>,
cho@microsoft.com, decui@microsoft.com,
John.Starks@microsoft.com,
Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH v6 0/6] x86/tdx: Allow MMIO instructions from userspace
Date: Fri, 6 Sep 2024 09:19:28 -0700 [thread overview]
Message-ID: <6c158a14-ba01-4146-9c6c-8e4c035dd055@intel.com> (raw)
In-Reply-To: <cover.1725622408.git.legion@kernel.org>
On 9/6/24 04:49, Alexey Gladkov wrote:
> Currently, MMIO inside the TDX guest is allowed from kernel space and access
> from userspace is denied. This becomes a problem when working with virtual
> devices in userspace.
Kernel MMIO and User MMIO are very different beasts.
The kernel MMIO instructions are trusted and can be constrained to use a
very limited number of instructions that match the kernel's limited
instruction decoding capability.
Userspace is not constrained in that way.
TDX also doesn't have the option of having the VMM deal with the
instruction emulation.
Before we start down this road, I'd really want to hear from the KVM
folks that having the kernel decode arbitrary user instructions is the
way we want to go.
next prev parent reply other threads:[~2024-09-06 16:19 UTC|newest]
Thread overview: 109+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-30 17:35 [PATCH v1 0/4] " Alexey Gladkov (Intel)
2024-07-30 17:35 ` [PATCH v1 1/4] x86/tdx: Split MMIO read and write operations Alexey Gladkov (Intel)
2024-07-30 18:31 ` Thomas Gleixner
2024-08-05 12:48 ` Alexey Gladkov
2024-07-30 17:35 ` [PATCH v1 2/4] x86/tdx: Add validation of userspace MMIO instructions Alexey Gladkov (Intel)
2024-07-30 18:34 ` Thomas Gleixner
2024-08-02 7:41 ` Kirill A. Shutemov
2024-08-05 12:50 ` Alexey Gladkov
2024-07-30 17:35 ` [PATCH v1 3/4] x86/tdx: Allow MMIO from userspace Alexey Gladkov (Intel)
2024-07-30 18:36 ` Thomas Gleixner
2024-07-30 17:35 ` [PATCH v1 4/4] x86/tdx: Implement movs for MMIO Alexey Gladkov (Intel)
2024-07-30 18:41 ` Thomas Gleixner
2024-08-05 12:51 ` Alexey Gladkov
2024-08-05 13:29 ` [PATCH v2 0/5] x86/tdx: Allow MMIO instructions from userspace Alexey Gladkov (Intel)
2024-08-05 13:29 ` [PATCH v2 1/5] x86/tdx: Split MMIO read and write operations Alexey Gladkov (Intel)
2024-08-05 13:29 ` [PATCH v2 2/5] x86/tdx: Add validation of userspace MMIO instructions Alexey Gladkov (Intel)
2024-08-05 22:40 ` Edgecombe, Rick P
2024-08-06 7:18 ` kirill.shutemov
2024-08-06 11:11 ` Alexey Gladkov
2024-08-06 11:41 ` Reshetova, Elena
2024-08-08 15:56 ` Alexey Gladkov
2024-08-08 15:53 ` Alexey Gladkov
2024-08-08 15:42 ` [PATCH v3 6/7] x86/tdx: Add a restriction on access to MMIO address Alexey Gladkov (Intel)
2024-08-08 15:42 ` [PATCH v3 7/7] x86/tdx: Avoid crossing the page boundary Alexey Gladkov (Intel)
2024-08-05 13:29 ` [PATCH v2 3/5] x86/tdx: Allow MMIO from userspace Alexey Gladkov (Intel)
2024-08-05 13:29 ` [PATCH v2 4/5] x86/tdx: Move MMIO helpers to common library Alexey Gladkov (Intel)
2024-08-05 13:29 ` [PATCH v2 5/5] x86/tdx: Implement movs for MMIO Alexey Gladkov (Intel)
2024-08-08 13:48 ` Tom Lendacky
2024-08-08 15:42 ` Alexey Gladkov
2024-08-08 16:53 ` Alexey Gladkov
2024-08-16 13:43 ` [PATCH v3 00/10] x86/tdx: Allow MMIO instructions from userspace Alexey Gladkov
2024-08-16 13:43 ` [PATCH v3 01/10] x86/tdx: Split MMIO read and write operations Alexey Gladkov
2024-08-19 10:19 ` Kirill A. Shutemov
2024-08-16 13:43 ` [PATCH v3 02/10] x86/tdx: Add validation of userspace MMIO instructions Alexey Gladkov
2024-08-19 10:39 ` Kirill A. Shutemov
2024-08-19 11:48 ` Alexey Gladkov
2024-08-19 12:07 ` Kirill A. Shutemov
2024-08-19 12:39 ` Alexey Gladkov
2024-08-16 13:43 ` [PATCH v3 03/10] x86/tdx: Allow MMIO from userspace Alexey Gladkov
2024-08-19 10:46 ` Kirill A. Shutemov
2024-08-19 11:50 ` Alexey Gladkov
2024-08-16 13:43 ` [PATCH v3 04/10] x86/insn: Read and decode insn without crossing the page boundary Alexey Gladkov
2024-08-17 3:28 ` kernel test robot
2024-08-19 10:48 ` Kirill A. Shutemov
2024-08-19 11:56 ` Alexey Gladkov
2024-08-19 12:08 ` Kirill A. Shutemov
2024-08-16 13:43 ` [PATCH v3 05/10] x86/tdx: Avoid " Alexey Gladkov
2024-08-16 13:43 ` [PATCH v3 06/10] x86/sev: " Alexey Gladkov
2024-08-16 13:43 ` [PATCH v3 07/10] x86/umip: " Alexey Gladkov
2024-08-16 13:43 ` [PATCH v3 08/10] x86/tdx: Add a restriction on access to MMIO address Alexey Gladkov
2024-08-16 13:43 ` [PATCH v3 09/10] x86/tdx: Move MMIO helpers to common library Alexey Gladkov
2024-08-16 13:44 ` [PATCH v3 10/10] x86/tdx: Implement movs for MMIO Alexey Gladkov
2024-08-21 14:24 ` [PATCH v4 0/6] x86/tdx: Allow MMIO instructions from userspace Alexey Gladkov
2024-08-21 14:24 ` [PATCH v4 1/6] x86/tdx: Split MMIO read and write operations Alexey Gladkov
2024-08-21 14:24 ` [PATCH v4 2/6] x86/tdx: Add validation of userspace MMIO instructions Alexey Gladkov
2024-08-22 7:16 ` Kirill A. Shutemov
2024-08-21 14:24 ` [PATCH v4 3/6] x86/tdx: Allow MMIO from userspace Alexey Gladkov
2024-08-22 7:18 ` Kirill A. Shutemov
2024-08-21 14:24 ` [PATCH v4 4/6] x86/tdx: Add a restriction on access to MMIO address Alexey Gladkov
2024-08-22 8:18 ` Kirill A. Shutemov
2024-08-21 14:24 ` [PATCH v4 5/6] x86/tdx: Move MMIO helpers to common library Alexey Gladkov
2024-08-22 8:23 ` Kirill A. Shutemov
2024-08-21 14:24 ` [PATCH v4 6/6] x86/tdx: Implement movs for MMIO Alexey Gladkov
2024-08-22 8:28 ` Kirill A. Shutemov
2024-08-24 16:57 ` Alexey Gladkov
2024-08-28 10:44 ` [PATCH v5 0/6] x86/tdx: Allow MMIO instructions from userspace Alexey Gladkov
2024-08-28 10:44 ` [PATCH v5 1/6] x86/tdx: Split MMIO read and write operations Alexey Gladkov
2024-08-28 10:44 ` [PATCH v5 2/6] x86/tdx: Add validation of userspace MMIO instructions Alexey Gladkov
2024-08-28 10:44 ` [PATCH v5 3/6] x86/tdx: Allow MMIO from userspace Alexey Gladkov
2024-08-28 10:44 ` [PATCH v5 4/6] x86/tdx: Add a restriction on access to MMIO address Alexey Gladkov
2024-08-29 12:30 ` Kirill A. Shutemov
2024-08-28 10:44 ` [PATCH v5 5/6] x86/tdx: Move MMIO helpers to common library Alexey Gladkov
2024-08-28 10:44 ` [PATCH v5 6/6] x86/tdx: Implement MOVS for MMIO Alexey Gladkov
2024-08-29 12:44 ` Kirill A. Shutemov
2024-08-29 18:40 ` Alexey Gladkov
2024-09-09 9:17 ` Kirill A. Shutemov
2024-09-06 11:49 ` [PATCH v6 0/6] x86/tdx: Allow MMIO instructions from userspace Alexey Gladkov
2024-09-06 11:49 ` [PATCH v6 1/6] x86/tdx: Fix "in-kernel MMIO" check Alexey Gladkov
2024-09-10 19:54 ` Dave Hansen
2024-09-11 12:08 ` Alexey Gladkov
2024-09-11 13:03 ` Kirill A. Shutemov
2024-09-10 19:59 ` Kirill A. Shutemov
2024-09-06 11:50 ` [PATCH v6 2/6] x86/tdx: Split MMIO read and write operations Alexey Gladkov
2024-09-06 11:50 ` [PATCH v6 3/6] x86/tdx: Add validation of userspace MMIO instructions Alexey Gladkov
2024-09-06 11:50 ` [PATCH v6 4/6] x86/tdx: Allow MMIO from userspace Alexey Gladkov
2024-09-06 11:50 ` [PATCH v6 5/6] x86/tdx: Move MMIO helpers to common library Alexey Gladkov
2024-09-09 9:19 ` Kirill A. Shutemov
2024-09-06 11:50 ` [PATCH v6 6/6] x86/tdx: Implement MOVS for MMIO Alexey Gladkov
2024-09-09 9:24 ` Kirill A. Shutemov
2024-09-06 16:19 ` Dave Hansen [this message]
2024-09-06 21:13 ` [PATCH v6 0/6] x86/tdx: Allow MMIO instructions from userspace Sean Christopherson
2024-09-11 15:38 ` Dave Hansen
2024-09-11 16:19 ` Sean Christopherson
2024-09-12 9:45 ` Kirill A. Shutemov
2024-09-12 15:49 ` Dave Hansen
2024-09-13 15:53 ` Kirill A. Shutemov
2024-09-13 16:01 ` Dave Hansen
2024-09-13 16:28 ` Sean Christopherson
2024-09-13 16:47 ` Dave Hansen
2024-09-13 17:39 ` Sean Christopherson
2024-09-13 17:05 ` [PATCH v7 " Alexey Gladkov
2024-09-13 17:05 ` [PATCH v7 1/6] x86/tdx: Fix "in-kernel MMIO" check Alexey Gladkov
2024-09-13 17:18 ` Dave Hansen
2024-09-13 17:23 ` Dave Hansen
2024-09-13 17:05 ` [PATCH v7 2/6] x86/tdx: Split MMIO read and write operations Alexey Gladkov
2024-09-13 17:05 ` [PATCH v7 3/6] x86/tdx: Add validation of userspace MMIO instructions Alexey Gladkov
2024-09-13 17:05 ` [PATCH v7 4/6] x86/tdx: Allow MMIO from userspace Alexey Gladkov
2024-09-13 17:06 ` [PATCH v7 5/6] x86/tdx: Move MMIO helpers to common library Alexey Gladkov
2024-09-13 17:06 ` [PATCH v7 6/6] x86/tdx: Implement MOVS for MMIO Alexey Gladkov
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