From 334b8ad7b182fc14d720acd7729afda3ab4c7e3a Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Sun, 3 May 2009 16:34:21 +0300 Subject: KVM: Fix NX support reporting NX support is bit 20, not bit 1. Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 7c1ce5ac6131..834a7bf25e48 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1259,7 +1259,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, bit(X86_FEATURE_CMOV) | bit(X86_FEATURE_PSE36) | bit(X86_FEATURE_MMX) | bit(X86_FEATURE_FXSR) | bit(X86_FEATURE_SYSCALL) | - (bit(X86_FEATURE_NX) && is_efer_nx()) | + (is_efer_nx() ? bit(X86_FEATURE_NX) : 0) | #ifdef CONFIG_X86_64 bit(X86_FEATURE_LM) | #endif -- cgit v1.2.2 From e286e86e6d2042d67d09244aa0e05ffef75c9d54 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Sun, 3 May 2009 18:50:55 +0300 Subject: KVM: Make EFER reads safe when EFER does not exist Some processors don't have EFER; don't oops if userspace wants us to read EFER when we check NX. Cc: stable@kernel.org Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 834a7bf25e48..49079a46687b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1121,9 +1121,9 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) static int is_efer_nx(void) { - u64 efer; + unsigned long long efer = 0; - rdmsrl(MSR_EFER, efer); + rdmsrl_safe(MSR_EFER, &efer); return efer & EFER_NX; } -- cgit v1.2.2 From a2edf57f510cce6a389cc14e58c6ad0a4296d6f9 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Sun, 24 May 2009 22:19:00 +0300 Subject: KVM: Fix PDPTR reloading on CR4 writes The processor is documented to reload the PDPTRs while in PAE mode if any of the CR4 bits PSE, PGE, or PAE change. Linux relies on this behaviour when zapping the low mappings of PAE kernels during boot. The code already handled changes to CR4.PAE; augment it to also notice changes to PSE and PGE. This triggered while booting an F11 PAE kernel; the futex initialization code runs before any CR3 reloads and writes to a NULL pointer; the futex subsystem ended up uninitialized, killing PI futexes and pulseaudio which uses them. Cc: stable@kernel.org Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 49079a46687b..3944e917e794 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -338,6 +338,9 @@ EXPORT_SYMBOL_GPL(kvm_lmsw); void kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) { + unsigned long old_cr4 = vcpu->arch.cr4; + unsigned long pdptr_bits = X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE; + if (cr4 & CR4_RESERVED_BITS) { printk(KERN_DEBUG "set_cr4: #GP, reserved bits\n"); kvm_inject_gp(vcpu, 0); @@ -351,7 +354,8 @@ void kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4) kvm_inject_gp(vcpu, 0); return; } - } else if (is_paging(vcpu) && !is_pae(vcpu) && (cr4 & X86_CR4_PAE) + } else if (is_paging(vcpu) && (cr4 & X86_CR4_PAE) + && ((cr4 ^ old_cr4) & pdptr_bits) && !load_pdptrs(vcpu, vcpu->arch.cr3)) { printk(KERN_DEBUG "set_cr4: #GP, pdptrs reserved bits\n"); kvm_inject_gp(vcpu, 0); -- cgit v1.2.2