From: Nikunj A Dadhania <nikunj@amd.com>
To: <linux-kernel@vger.kernel.org>, <thomas.lendacky@amd.com>,
<x86@kernel.org>, <kvm@vger.kernel.org>
Cc: <bp@alien8.de>, <mingo@redhat.com>, <tglx@linutronix.de>,
<dave.hansen@linux.intel.com>, <dionnaglaze@google.com>,
<pgonda@google.com>, <seanjc@google.com>, <pbonzini@redhat.com>,
<nikunj@amd.com>
Subject: [PATCH v6 12/16] x86/sev: Prevent RDTSC/RDTSCP interception for Secure TSC enabled guests
Date: Tue, 28 Nov 2023 18:29:55 +0530 [thread overview]
Message-ID: <20231128125959.1810039-13-nikunj@amd.com> (raw)
In-Reply-To: <20231128125959.1810039-1-nikunj@amd.com>
The hypervisor should not be intercepting RDTSC/RDTSCP when Secure TSC
is enabled. A #VC exception will be generated if the RDTSC/RDTSCP
instructions are being intercepted. If this should occur and Secure
TSC is enabled, terminate guest execution.
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
---
arch/x86/kernel/sev-shared.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index ccb0915e84e1..6d9ef5897421 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -991,6 +991,16 @@ static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,
bool rdtscp = (exit_code == SVM_EXIT_RDTSCP);
enum es_result ret;
+ /*
+ * RDTSC and RDTSCP should not be intercepted when Secure TSC is
+ * enabled. Terminate the SNP guest when the interception is enabled.
+ * This file is included from kernel/sev.c and boot/compressed/sev.c,
+ * use sev_status here as cc_platform_has() is not available when
+ * compiling boot/compressed/sev.c.
+ */
+ if (sev_status & MSR_AMD64_SNP_SECURE_TSC)
+ return ES_VMM_ERROR;
+
ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0);
if (ret != ES_OK)
return ret;
--
2.34.1
next prev parent reply other threads:[~2023-11-28 13:02 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-28 12:59 [PATCH v6 00/16] Add Secure TSC support for SNP guests Nikunj A Dadhania
2023-11-28 12:59 ` [PATCH v6 01/16] virt: sev-guest: Use AES GCM crypto library Nikunj A Dadhania
2023-11-28 12:59 ` [PATCH v6 02/16] virt: sev-guest: Move mutex to SNP guest device structure Nikunj A Dadhania
2023-11-28 12:59 ` [PATCH v6 03/16] virt: sev-guest: Replace dev_dbg with pr_debug Nikunj A Dadhania
2023-11-28 12:59 ` [PATCH v6 04/16] virt: sev-guest: Add SNP guest request structure Nikunj A Dadhania
2023-11-28 12:59 ` [PATCH v6 05/16] virt: sev-guest: Add vmpck_id to snp_guest_dev struct Nikunj A Dadhania
2023-11-28 12:59 ` [PATCH v6 06/16] x86/sev: Cache the secrets page address Nikunj A Dadhania
2023-12-06 22:21 ` Dionna Amalie Glaze
2023-12-07 6:06 ` Nikunj A. Dadhania
2023-11-28 12:59 ` [PATCH v6 07/16] x86/sev: Move and reorganize sev guest request api Nikunj A Dadhania
2023-11-28 22:50 ` kernel test robot
2023-11-29 2:40 ` kernel test robot
2023-12-05 17:13 ` Dionna Amalie Glaze
2023-12-06 4:24 ` Nikunj A. Dadhania
2023-11-28 12:59 ` [PATCH v6 08/16] x86/mm: Add generic guest initialization hook Nikunj A Dadhania
2023-11-28 12:59 ` [PATCH v6 09/16] x86/cpufeatures: Add synthetic Secure TSC bit Nikunj A Dadhania
2023-11-28 12:59 ` [PATCH v6 10/16] x86/sev: Add Secure TSC support for SNP guests Nikunj A Dadhania
2023-11-29 4:08 ` kernel test robot
2023-11-28 12:59 ` [PATCH v6 11/16] x86/sev: Change TSC MSR behavior for Secure TSC enabled guests Nikunj A Dadhania
2023-11-28 12:59 ` Nikunj A Dadhania [this message]
2023-12-05 17:16 ` [PATCH v6 12/16] x86/sev: Prevent RDTSC/RDTSCP interception " Dionna Amalie Glaze
2023-12-06 4:37 ` Nikunj A. Dadhania
2023-12-06 18:45 ` Dionna Amalie Glaze
2023-12-07 6:12 ` Nikunj A. Dadhania
2023-11-28 12:59 ` [PATCH v6 13/16] x86/kvmclock: Skip kvmclock when Secure TSC is available Nikunj A Dadhania
2023-11-28 12:59 ` [PATCH v6 14/16] x86/sev: Mark Secure TSC as reliable Nikunj A Dadhania
2023-11-28 12:59 ` [PATCH v6 15/16] x86/cpu/amd: Do not print FW_BUG for Secure TSC Nikunj A Dadhania
2023-11-28 12:59 ` [PATCH v6 16/16] x86/sev: Enable Secure TSC for SNP guests Nikunj A Dadhania
2023-12-06 17:46 ` [PATCH v6 00/16] Add Secure TSC support " Peter Gonda
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