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AJvYcCUekVbGVEdVjBvFg6bE4O2LOovVQBa8iSHzkePfTMTTPV8l88Cwd6eaZDiCwF2PBUrmiWi0I3RGeibVcAYmUH35tI3CLHwYrE30iChtgwfksti/W0S1LeOhL5TWrhU+mnv94xIzkyA2Syx2N1Dfp5n0p9G5ba4BVbY+ X-Gm-Message-State: AOJu0YzJLjJ54C92GovaaD7VsysyxomjaZpvc32NPlUmFJs06owiOZl2 TMAzAssqLwfwUc5tunjh5TR9vhqd3TsJOO9+wfcvMa+X03i9UZqJ X-Google-Smtp-Source: AGHT+IE8QCaOWgeggvX3bzfdgpzjd9AKZpVWk5t3o1rNmV0yg4I7I6xr4BI4sOPOf3U8/XIcokRopQ== X-Received: by 2002:a05:600c:350f:b0:416:7071:6eff with SMTP id h15-20020a05600c350f00b0041670716effmr1229085wmq.41.1712562073135; Mon, 08 Apr 2024 00:41:13 -0700 (PDT) Received: from vasant-suse.suse.cz ([2001:9e8:ab70:9c00:7f0b:c18e:56a6:4f2]) by smtp.gmail.com with ESMTPSA id j3-20020adfff83000000b00341e2146b53sm8271413wrr.106.2024.04.08.00.41.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Apr 2024 00:41:12 -0700 (PDT) From: vsntk18@gmail.com To: x86@kernel.org Cc: cfir@google.com, dan.j.williams@intel.com, dave.hansen@linux.intel.com, ebiederm@xmission.com, erdemaktas@google.com, hpa@zytor.com, jgross@suse.com, jroedel@suse.de, jslaby@suse.cz, keescook@chromium.org, kexec@lists.infradead.org, kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, luto@kernel.org, martin.b.radev@gmail.com, mhiramat@kernel.org, mstunes@vmware.com, nivedita@alum.mit.edu, peterz@infradead.org, rientjes@google.com, seanjc@google.com, stable@vger.kernel.org, thomas.lendacky@amd.com, virtualization@lists.linux-foundation.org, vkarasulli@suse.de, ashish.kalra@amd.com, michael.roth@amd.com, Borislav.Petkov@amd.com, Dhaval.Giani@amd.com Subject: [PATCH v5 06/10] x86/sev: Use AP Jump Table blob to stop CPU Date: Mon, 8 Apr 2024 09:40:45 +0200 Message-Id: <20240408074049.7049-7-vsntk18@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240408074049.7049-1-vsntk18@gmail.com> References: <20240408074049.7049-1-vsntk18@gmail.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Joerg Roedel To support kexec under SEV-ES the APs can't be parked with HLT. Upon wakeup the AP needs to find its way to execute at the reset vector set by the new kernel and in real-mode. This is what the AP jump table blob provides, so stop the APs the SEV-ES way by calling the AP-reset-hold VMGEXIT from the AP jump table. Signed-off-by: Joerg Roedel Signed-off-by: Vasant Karasulli --- arch/x86/include/asm/sev.h | 2 ++ arch/x86/kernel/process.c | 8 ++++++++ arch/x86/kernel/sev.c | 15 ++++++++++++++- 3 files changed, 24 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index 829650bdd455..dba6cad1f7d3 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -233,6 +233,7 @@ u64 snp_get_unsupported_features(u64 status); u64 sev_get_status(void); void kdump_sev_callback(void); void sev_show_status(void); +void sev_es_stop_this_cpu(void); #else static inline void sev_es_ist_enter(struct pt_regs *regs) { } static inline void sev_es_ist_exit(void) { } @@ -263,6 +264,7 @@ static inline u64 snp_get_unsupported_features(u64 status) { return 0; } static inline u64 sev_get_status(void) { return 0; } static inline void kdump_sev_callback(void) { } static inline void sev_show_status(void) { } +static inline void sev_es_stop_this_cpu(void) { } #endif #ifdef CONFIG_KVM_AMD_SEV diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index b8441147eb5e..0bc615d69c0e 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -52,6 +52,7 @@ #include #include #include +#include #include "process.h" @@ -836,6 +837,13 @@ void __noreturn stop_this_cpu(void *dummy) cpumask_clear_cpu(cpu, &cpus_stop_mask); for (;;) { + /* + * SEV-ES guests need a special stop routine to support + * kexec. Try this first, if it fails the function will + * return and native_halt() is used. + */ + sev_es_stop_this_cpu(); + /* * Use native_halt() so that memory contents don't change * (stack usage and variables) after possibly issuing the diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 4c235e310487..17e4263cc7d7 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -1357,7 +1357,6 @@ void setup_ghcb(void) snp_register_ghcb_early(__pa(&boot_ghcb_page)); } -#ifdef CONFIG_HOTPLUG_CPU void __noreturn sev_jumptable_ap_park(void) { local_irq_disable(); @@ -1390,6 +1389,20 @@ void __noreturn sev_jumptable_ap_park(void) } STACK_FRAME_NON_STANDARD(sev_jumptable_ap_park); +void sev_es_stop_this_cpu(void) +{ + if (!(cc_vendor == CC_VENDOR_AMD) || + !cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) + return; + + /* Only park in the AP jump table when the code has been installed */ + if (!sev_ap_jumptable_blob_installed) + return; + + sev_jumptable_ap_park(); +} + +#ifdef CONFIG_HOTPLUG_CPU static void sev_es_ap_hlt_loop(void) { struct ghcb_state state;