From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Peter Zijlstra <peterz@infradead.org>,
Andy Lutomirski <luto@kernel.org>
Cc: 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>,
Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
Sean Christopherson <seanjc@google.com>,
Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>,
linux-kernel@vger.kernel.org, x86@kernel.org
Subject: [PATCH v1 11/11] x86/tdx: Handle CPUID via #VE
Date: Tue, 1 Jun 2021 19:21:36 -0700 [thread overview]
Message-ID: <20210602022136.2186759-12-sathyanarayanan.kuppuswamy@linux.intel.com> (raw)
In-Reply-To: <20210602022136.2186759-1-sathyanarayanan.kuppuswamy@linux.intel.com>
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
TDX has three classes of CPUID leaves: some CPUID leaves
are always handled by the CPU, others are handled by the TDX module,
and some others are handled by the VMM. Since the VMM cannot directly
intercept the instruction these are reflected with a #VE exception
to the guest, which then converts it into a hypercall to the VMM,
or handled directly.
The TDX module EAS has a full list of CPUID leaves which are handled
natively or by the TDX module in 16.2. Only unknown CPUIDs are handled by
the #VE method. In practice this typically only applies to the
hypervisor specific CPUIDs unknown to the native CPU.
Therefore there is no risk of causing this in early CPUID code which
runs before the #VE handler is set up because it will never access
those exotic CPUID leaves.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---
arch/x86/kernel/tdx.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/arch/x86/kernel/tdx.c b/arch/x86/kernel/tdx.c
index af7acea500ab..17725646eb30 100644
--- a/arch/x86/kernel/tdx.c
+++ b/arch/x86/kernel/tdx.c
@@ -164,6 +164,22 @@ static int tdg_write_msr_safe(unsigned int msr, unsigned int low,
return ret ? -EIO : 0;
}
+static void tdg_handle_cpuid(struct pt_regs *regs)
+{
+ u64 ret;
+ struct tdx_hypercall_output out = {0};
+
+ ret = __tdx_hypercall(EXIT_REASON_CPUID, regs->ax,
+ regs->cx, 0, 0, &out);
+
+ WARN_ON(ret);
+
+ regs->ax = out.r12;
+ regs->bx = out.r13;
+ regs->cx = out.r14;
+ regs->dx = out.r15;
+}
+
unsigned long tdg_get_ve_info(struct ve_info *ve)
{
u64 ret;
@@ -207,6 +223,9 @@ int tdg_handle_virtualization_exception(struct pt_regs *regs,
case EXIT_REASON_MSR_WRITE:
ret = tdg_write_msr_safe(regs->cx, regs->ax, regs->dx);
break;
+ case EXIT_REASON_CPUID:
+ tdg_handle_cpuid(regs);
+ break;
default:
pr_warn("Unexpected #VE: %lld\n", ve->exit_reason);
return -EFAULT;
--
2.25.1
next prev parent reply other threads:[~2021-06-02 2:22 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-02 2:21 [PATCH v1 00/11] Add TDX Guest Support (Initial support) Kuppuswamy Sathyanarayanan
2021-06-02 2:21 ` [PATCH v1 01/11] x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT Kuppuswamy Sathyanarayanan
2021-06-02 2:21 ` [PATCH v1 02/11] x86/tdx: Introduce INTEL_TDX_GUEST config option Kuppuswamy Sathyanarayanan
2021-06-02 2:21 ` [PATCH v1 03/11] x86/cpufeatures: Add TDX Guest CPU feature Kuppuswamy Sathyanarayanan
2021-06-07 14:32 ` Tom Lendacky
2021-06-07 16:59 ` Kuppuswamy, Sathyanarayanan
2021-06-10 12:28 ` Borislav Petkov
2021-06-10 14:28 ` Kuppuswamy, Sathyanarayanan
2021-06-10 14:29 ` Kirill A. Shutemov
2021-06-10 14:35 ` Borislav Petkov
2021-06-10 14:41 ` Kirill A. Shutemov
2021-06-10 15:56 ` Borislav Petkov
2021-06-12 21:02 ` [PATCH v2 03/12] " Kuppuswamy Sathyanarayanan
2021-06-16 9:52 ` Borislav Petkov
2021-06-16 16:57 ` Kuppuswamy, Sathyanarayanan
2021-06-02 2:21 ` [PATCH v1 04/11] x86/x86: Add is_tdx_guest() interface Kuppuswamy Sathyanarayanan
2021-06-10 19:59 ` Borislav Petkov
2021-06-10 21:01 ` Kuppuswamy, Sathyanarayanan
2021-06-10 21:07 ` Borislav Petkov
2021-06-12 21:04 ` [PATCH v2 04/12] x86/x86: Add early_is_tdx_guest() interface Kuppuswamy Sathyanarayanan
2021-06-17 17:05 ` Borislav Petkov
2021-06-18 19:14 ` Kuppuswamy, Sathyanarayanan
2021-06-02 2:21 ` [PATCH v1 05/11] x86/tdx: Add __tdx_module_call() and __tdx_hypercall() helper functions Kuppuswamy Sathyanarayanan
2021-06-14 8:47 ` Borislav Petkov
2021-06-14 19:45 ` Kuppuswamy, Sathyanarayanan
2021-06-14 20:11 ` Borislav Petkov
2021-06-14 21:37 ` Kuppuswamy, Sathyanarayanan
2021-06-02 2:21 ` [PATCH v1 06/11] x86/tdx: Get TD execution environment information via TDINFO Kuppuswamy Sathyanarayanan
2021-06-02 2:21 ` [PATCH v1 07/11] x86/traps: Add #VE support for TDX guest Kuppuswamy Sathyanarayanan
2021-06-02 2:21 ` [PATCH v1 08/11] x86/tdx: Add HLT " Kuppuswamy Sathyanarayanan
2021-06-02 2:21 ` [PATCH v1 09/11] x86/tdx: Wire up KVM hypercalls Kuppuswamy Sathyanarayanan
2021-06-12 21:08 ` [PATCH v2 10/12] " Kuppuswamy Sathyanarayanan
2021-06-02 2:21 ` [PATCH v1 10/11] x86/tdx: Add MSR support for TDX guest Kuppuswamy Sathyanarayanan
2021-06-02 2:21 ` Kuppuswamy Sathyanarayanan [this message]
-- strict thread matches above, loose matches on Subject: below --
2021-06-02 2:19 Kuppuswamy Sathyanarayanan
2021-06-02 2:19 ` [PATCH v1 11/11] x86/tdx: Handle CPUID via #VE Kuppuswamy Sathyanarayanan
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=20210602022136.2186759-12-sathyanarayanan.kuppuswamy@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 \
/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.