From 37817f2982d0f559f90cecc66e150dd9d2c2df05 Mon Sep 17 00:00:00 2001 From: Izik Eidus Date: Mon, 24 Mar 2008 23:14:53 +0200 Subject: KVM: x86: hardware task switching support This emulates the x86 hardware task switch mechanism in software, as it is unsupported by either vmx or svm. It allows operating systems which use it, like freedos, to run as kvm guests. Signed-off-by: Izik Eidus Signed-off-by: Avi Kivity --- arch/x86/kvm/vmx.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'arch/x86/kvm/vmx.c') diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 9b560325b127..cbca46acfac3 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2249,6 +2249,20 @@ static int handle_apic_access(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) return 1; } +static int handle_task_switch(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) +{ + unsigned long exit_qualification; + u16 tss_selector; + int reason; + + exit_qualification = vmcs_readl(EXIT_QUALIFICATION); + + reason = (u32)exit_qualification >> 30; + tss_selector = exit_qualification; + + return kvm_task_switch(vcpu, tss_selector, reason); +} + /* * The exit handlers return 1 if the exit was handled fully and guest execution * may resume. Otherwise they set the kvm_run parameter to indicate what needs @@ -2271,6 +2285,7 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu, [EXIT_REASON_TPR_BELOW_THRESHOLD] = handle_tpr_below_threshold, [EXIT_REASON_APIC_ACCESS] = handle_apic_access, [EXIT_REASON_WBINVD] = handle_wbinvd, + [EXIT_REASON_TASK_SWITCH] = handle_task_switch, }; static const int kvm_vmx_max_exit_handlers = -- cgit v1.2.2