Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759139Ab0G3R1A (ORCPT ); Fri, 30 Jul 2010 13:27:00 -0400 Received: from kroah.org ([198.145.64.141]:52140 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758863Ab0G3RUB (ORCPT ); Fri, 30 Jul 2010 13:20:01 -0400 X-Mailbox-Line: From gregkh@clark.site Fri Jul 30 10:15:11 2010 Message-Id: <20100730171511.885912147@clark.site> User-Agent: quilt/0.48-11.2 Date: Fri, 30 Jul 2010 10:16:03 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Joerg Roedel , Jan Kiszka , Xiao Guangrong , Avi Kivity Subject: [135/165] KVM: SVM: Implement workaround for Erratum 383 In-Reply-To: <20100730171550.GA1299@kroah.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4408 Lines: 171 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ This patch implements a workaround for AMD erratum 383 into KVM. Without this erratum fix it is possible for a guest to kill the host machine. This patch implements the suggested workaround for hypervisors which will be published by the next revision guide update. [jan: fix overflow warning on i386] [xiao: fix unused variable warning] Cc: stable@kernel.org Signed-off-by: Joerg Roedel Signed-off-by: Jan Kiszka Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity (cherry picked from commit 67ec66077799f2fef84b21a643912b179c422281) --- arch/x86/include/asm/msr-index.h | 1 arch/x86/kvm/svm.c | 84 ++++++++++++++++++++++++++++++++++++++- 2 files changed, 84 insertions(+), 1 deletion(-) --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -106,6 +106,7 @@ #define MSR_AMD64_PATCH_LOADER 0xc0010020 #define MSR_AMD64_OSVW_ID_LENGTH 0xc0010140 #define MSR_AMD64_OSVW_STATUS 0xc0010141 +#define MSR_AMD64_DC_CFG 0xc0011022 #define MSR_AMD64_IBSFETCHCTL 0xc0011030 #define MSR_AMD64_IBSFETCHLINAD 0xc0011031 #define MSR_AMD64_IBSFETCHPHYSAD 0xc0011032 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -27,6 +27,7 @@ #include #include +#include #include #include @@ -62,6 +63,8 @@ MODULE_LICENSE("GPL"); #define nsvm_printk(fmt, args...) do {} while(0) #endif +static bool erratum_383_found __read_mostly; + static const u32 host_save_user_msrs[] = { #ifdef CONFIG_X86_64 MSR_STAR, MSR_LSTAR, MSR_CSTAR, MSR_SYSCALL_MASK, MSR_KERNEL_GS_BASE, @@ -299,6 +302,31 @@ static void skip_emulated_instruction(st svm_set_interrupt_shadow(vcpu, 0); } +static void svm_init_erratum_383(void) +{ + u32 low, high; + int err; + u64 val; + + /* Only Fam10h is affected */ + if (boot_cpu_data.x86 != 0x10) + return; + + /* Use _safe variants to not break nested virtualization */ + val = native_read_msr_safe(MSR_AMD64_DC_CFG, &err); + if (err) + return; + + val |= (1ULL << 47); + + low = lower_32_bits(val); + high = upper_32_bits(val); + + native_write_msr_safe(MSR_AMD64_DC_CFG, low, high); + + erratum_383_found = true; +} + static int has_svm(void) { const char *msg; @@ -318,7 +346,6 @@ static void svm_hardware_disable(void *g static void svm_hardware_enable(void *garbage) { - struct svm_cpu_data *svm_data; uint64_t efer; struct descriptor_table gdt_descr; @@ -350,6 +377,10 @@ static void svm_hardware_enable(void *ga wrmsrl(MSR_VM_HSAVE_PA, page_to_pfn(svm_data->save_area) << PAGE_SHIFT); + + svm_init_erratum_383(); + + return; } static void svm_cpu_uninit(int cpu) @@ -1257,8 +1288,59 @@ static int nm_interception(struct vcpu_s return 1; } +static bool is_erratum_383(void) +{ + int err, i; + u64 value; + + if (!erratum_383_found) + return false; + + value = native_read_msr_safe(MSR_IA32_MC0_STATUS, &err); + if (err) + return false; + + /* Bit 62 may or may not be set for this mce */ + value &= ~(1ULL << 62); + + if (value != 0xb600000000010015ULL) + return false; + + /* Clear MCi_STATUS registers */ + for (i = 0; i < 6; ++i) + native_write_msr_safe(MSR_IA32_MCx_STATUS(i), 0, 0); + + value = native_read_msr_safe(MSR_IA32_MCG_STATUS, &err); + if (!err) { + u32 low, high; + + value &= ~(1ULL << 2); + low = lower_32_bits(value); + high = upper_32_bits(value); + + native_write_msr_safe(MSR_IA32_MCG_STATUS, low, high); + } + + /* Flush tlb to evict multi-match entries */ + __flush_tlb_all(); + + return true; +} + static void svm_handle_mce(struct vcpu_svm *svm) { + if (is_erratum_383()) { + /* + * Erratum 383 triggered. Guest state is corrupt so kill the + * guest. + */ + pr_err("KVM: Guest triggered AMD Erratum 383\n"); + + set_bit(KVM_REQ_TRIPLE_FAULT, &svm->vcpu.requests); + + return; + } + /* * On an #MC intercept the MCE handler is not called automatically in * the host. So do it by hand here. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/