On Mon, Mar 07, 2011 at 05:19:36PM +0200, Gleb Natapov wrote: > Commit 6440e5967bc broke old userspaces that do not set tss address > before entering vcpu. Unbreak it by setting tss address to a safe > value on the first vcpu entry. New userspaces should set tss address, > so print warning in case it doesn't. > > Signed-off-by: Gleb Natapov <[email protected]> > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index e2b8c6b..280b6ea 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -180,6 +180,7 @@ static u64 construct_eptp(unsigned long root_hpa); > static void kvm_cpu_vmxon(u64 addr); > static void kvm_cpu_vmxoff(void); > static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3); > +static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr); > > static DEFINE_PER_CPU(struct vmcs *, vmxarea); > static DEFINE_PER_CPU(struct vmcs *, current_vmcs); > @@ -1762,6 +1763,16 @@ static void enter_rmode(struct kvm_vcpu *vcpu) > vmx->emulation_required = 1; > vmx->rmode.vm86_active = 1; > > + /* > + * Very old userspace does not call KVM_SET_TSS_ADDR before entering > + * vcpu. Call it here with phys address pointing 16M below 4G. > + */ > + if (!vcpu->kvm->arch.tss_addr) { > + printk_once(KERN_WARNING "kvm: KVM_SET_TSS_ADDR need to be " > + "called before entering vcpu\n"); > + vmx_set_tss_addr(vcpu->kvm, 0xfeffd000); > + } > + > vmx->rmode.tr.selector = vmcs_read16(GUEST_TR_SELECTOR); > vmx->rmode.tr.base = vmcs_readl(GUEST_TR_BASE); > vmcs_writel(GUEST_TR_BASE, rmode_tss_base(vcpu->kvm));
Should leave/enter srcu section before/after set_memory_region. Actually, for older userspace, isnt the base_gfn + slot[0].npages - 3 address (rmode_tss_base) used? That is, initializing the TSS page at that address at vcpu_reset time should be enough? -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
