From cafd66595d92591e4bd25c3904e004fc6f897e2d Mon Sep 17 00:00:00 2001 From: Shane Wang Date: Thu, 29 Apr 2010 12:09:01 -0400 Subject: [PATCH] KVM: VMX: enable VMXON check with SMX enabled (Intel TXT) Per document, for feature control MSR: Bit 1 enables VMXON in SMX operation. If the bit is clear, execution of VMXON in SMX operation causes a general-protection exception. Bit 2 enables VMXON outside SMX operation. If the bit is clear, execution of VMXON outside SMX operation causes a general-protection exception. This patch is to enable this kind of check with SMX for VMXON in KVM. Signed-off-by: Shane Wang Signed-off-by: Avi Kivity --- arch/x86/include/asm/msr-index.h | 5 +++-- arch/x86/kernel/tboot.c | 1 + arch/x86/kvm/vmx.c | 32 +++++++++++++++++++++----------- include/linux/tboot.h | 1 + 4 files changed, 26 insertions(+), 13 deletions(-) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index bc473ac..f932485 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -202,8 +202,9 @@ #define MSR_IA32_EBL_CR_POWERON 0x0000002a #define MSR_IA32_FEATURE_CONTROL 0x0000003a -#define FEATURE_CONTROL_LOCKED (1<<0) -#define FEATURE_CONTROL_VMXON_ENABLED (1<<2) +#define FEATURE_CONTROL_LOCKED (1<<0) +#define FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX (1<<1) +#define FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX (1<<2) #define MSR_IA32_APICBASE 0x0000001b #define MSR_IA32_APICBASE_BSP (1<<8) diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index 86c9f91..46b8277 100644 --- a/arch/x86/kernel/tboot.c +++ b/arch/x86/kernel/tboot.c @@ -46,6 +46,7 @@ /* Global pointer to shared data; NULL means no measured launch. */ struct tboot *tboot __read_mostly; +EXPORT_SYMBOL(tboot); /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */ #define AP_WAIT_TIMEOUT 1 diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c4f3955..d2a47ae 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -27,6 +27,7 @@ #include #include #include +#include #include "kvm_cache_regs.h" #include "x86.h" @@ -1272,9 +1273,16 @@ static __init int vmx_disabled_by_bios(void) u64 msr; rdmsrl(MSR_IA32_FEATURE_CONTROL, msr); - return (msr & (FEATURE_CONTROL_LOCKED | - FEATURE_CONTROL_VMXON_ENABLED)) - == FEATURE_CONTROL_LOCKED; + if (msr & FEATURE_CONTROL_LOCKED) { + if (!(msr & FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX) + && tboot_enabled()) + return 1; + if (!(msr & FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX) + && !tboot_enabled()) + return 1; + } + + return 0; /* locked but not enabled */ } @@ -1282,21 +1290,23 @@ static int hardware_enable(void *garbage) { int cpu = raw_smp_processor_id(); u64 phys_addr = __pa(per_cpu(vmxarea, cpu)); - u64 old; + u64 old, test_bits; if (read_cr4() & X86_CR4_VMXE) return -EBUSY; INIT_LIST_HEAD(&per_cpu(vcpus_on_cpu, cpu)); rdmsrl(MSR_IA32_FEATURE_CONTROL, old); - if ((old & (FEATURE_CONTROL_LOCKED | - FEATURE_CONTROL_VMXON_ENABLED)) - != (FEATURE_CONTROL_LOCKED | - FEATURE_CONTROL_VMXON_ENABLED)) + + test_bits = FEATURE_CONTROL_LOCKED; + test_bits |= FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX; + if (tboot_enabled()) + test_bits |= FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX; + + if ((old & test_bits) != test_bits) { /* enable and lock */ - wrmsrl(MSR_IA32_FEATURE_CONTROL, old | - FEATURE_CONTROL_LOCKED | - FEATURE_CONTROL_VMXON_ENABLED); + wrmsrl(MSR_IA32_FEATURE_CONTROL, old | test_bits); + } write_cr4(read_cr4() | X86_CR4_VMXE); /* FIXME: not cpu hotplug safe */ asm volatile (ASM_VMX_VMXON_RAX : : "a"(&phys_addr), "m"(phys_addr) diff --git a/include/linux/tboot.h b/include/linux/tboot.h index bf2a0c7..1dba6ee 100644 --- a/include/linux/tboot.h +++ b/include/linux/tboot.h @@ -150,6 +150,7 @@ extern int tboot_force_iommu(void); #else +#define tboot_enabled() 0 #define tboot_probe() do { } while (0) #define tboot_shutdown(shutdown_type) do { } while (0) #define tboot_sleep(sleep_state, pm1a_control, pm1b_control) \ -- 1.8.2.3