From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: [PATCH v3 71/75] x86/head/64: Don't call verify_cpu() on starting APs Date: Tue, 28 Apr 2020 17:17:21 +0200 Message-ID: <20200428151725.31091-72-joro@8bytes.org> References: <20200428151725.31091-1-joro@8bytes.org> Return-path: In-Reply-To: <20200428151725.31091-1-joro@8bytes.org> Sender: kvm-owner@vger.kernel.org To: x86@kernel.org Cc: hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Thomas Hellstrom , Jiri Slaby , Dan Williams , Tom Lendacky , Juergen Gross , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Joerg Roedel , Joerg Roedel , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org From: Joerg Roedel The APs are not ready to handle exceptions when verify_cpu() is called in secondary_startup_64. Signed-off-by: Joerg Roedel --- arch/x86/include/asm/realmode.h | 1 + arch/x86/kernel/head_64.S | 1 + arch/x86/realmode/init.c | 6 ++++++ 3 files changed, 8 insertions(+) diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h index 6590394af309..5c97807c38a4 100644 --- a/arch/x86/include/asm/realmode.h +++ b/arch/x86/include/asm/realmode.h @@ -69,6 +69,7 @@ extern unsigned char startup_32_smp[]; extern unsigned char boot_gdt[]; #else extern unsigned char secondary_startup_64[]; +extern unsigned char secondary_startup_64_no_verify[]; #endif static inline size_t real_mode_size_needed(void) diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 7f2d5e14db73..72b8f0834de1 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -150,6 +150,7 @@ SYM_CODE_START(secondary_startup_64) /* Sanitize CPU configuration */ call verify_cpu +SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) /* * Retrieve the modifier (SME encryption mask if SME is active) to be * added to the initial pgdir entry that will be programmed into CR3. diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c index 1c5cbfd102d5..030c38268069 100644 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -109,6 +109,12 @@ static void __init setup_real_mode(void) trampoline_header->flags |= TH_FLAGS_SME_ACTIVE; if (sev_es_active()) { + /* + * Skip the call to verify_cpu() in secondary_startup_64 as it + * will cause #VC exceptions when the AP can't handle them yet. + */ + trampoline_header->start = (u64) secondary_startup_64_no_verify; + if (sev_es_setup_ap_jump_table(real_mode_header)) panic("Failed to update SEV-ES AP Jump Table"); } -- 2.17.1