From: Suravee Suthikulpanit <[email protected]> When a vcpu is loaded/unloaded to a physical core, we need to update information in the Physical APIC-ID table accordingly.
Signed-off-by: Suravee Suthikulpanit <[email protected]> --- arch/x86/kvm/svm.c | 146 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 146 insertions(+) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 5142861..ebcade0 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -35,6 +35,7 @@ #include <linux/trace_events.h> #include <linux/slab.h> +#include <asm/apic.h> #include <asm/perf_event.h> #include <asm/tlbflush.h> #include <asm/desc.h> @@ -175,6 +176,7 @@ struct vcpu_svm { struct page *avic_bk_page; void *in_kernel_lapic_regs; + bool avic_was_running; }; struct __attribute__ ((__packed__)) @@ -1508,6 +1510,146 @@ static int avic_vcpu_init(struct kvm *kvm, struct vcpu_svm *svm, int id) return 0; } +static inline int +avic_update_iommu(struct kvm_vcpu *vcpu, int cpu, phys_addr_t pa, bool r) +{ + if (!kvm_arch_has_assigned_device(vcpu->kvm)) + return 0; + + /* TODO: We will hook up with IOMMU API at later time */ + return 0; +} + +static int avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu, bool is_load) +{ + int g_phy_apic_id, h_phy_apic_id; + struct svm_avic_phy_ait_entry *entry, new_entry; + struct vcpu_svm *svm = to_svm(vcpu); + int ret = 0; + + if (!avic) + return 0; + + if (!svm) + return -EINVAL; + + /* Note: APIC ID = 0xff is used for broadcast. + * APIC ID > 0xff is reserved. + */ + g_phy_apic_id = vcpu->vcpu_id; + h_phy_apic_id = __default_cpu_present_to_apicid(cpu); + + if ((g_phy_apic_id >= AVIC_PHY_APIC_ID_MAX) || + (h_phy_apic_id >= AVIC_PHY_APIC_ID_MAX)) + return -EINVAL; + + entry = avic_get_phy_ait_entry(vcpu, g_phy_apic_id); + if (!entry) + return -EINVAL; + + if (is_load) { + /* Handle vcpu load */ + phys_addr_t pa = PFN_PHYS(page_to_pfn(svm->avic_bk_page)); + + new_entry = READ_ONCE(*entry); + + BUG_ON(new_entry.is_running); + + new_entry.bk_pg_ptr = (pa >> 12) & 0xffffffffff; + new_entry.valid = 1; + new_entry.host_phy_apic_id = h_phy_apic_id; + + if (svm->avic_was_running) { + /** + * Restore AVIC running flag if it was set during + * vcpu unload. + */ + new_entry.is_running = 1; + } + ret = avic_update_iommu(vcpu, h_phy_apic_id, pa, + svm->avic_was_running); + WRITE_ONCE(*entry, new_entry); + + } else { + /* Handle vcpu unload */ + new_entry = READ_ONCE(*entry); + if (new_entry.is_running) { + phys_addr_t pa = PFN_PHYS(page_to_pfn(svm->avic_bk_page)); + + /** + * This handles the case when vcpu is scheduled out + * and has not yet not called blocking. We save the + * AVIC running flag so that we can restore later. + */ + svm->avic_was_running = true; + + /** + * We need to also clear the AVIC running flag + * and communicate the changes to IOMMU. + */ + ret = avic_update_iommu(vcpu, h_phy_apic_id, pa, 0); + + new_entry.is_running = 0; + WRITE_ONCE(*entry, new_entry); + } else { + svm->avic_was_running = false; + } + } + + return ret; +} + +/** + * This function is called during VCPU halt/unhalt. + */ +static int avic_set_running(struct kvm_vcpu *vcpu, bool is_run) +{ + int ret = 0; + int g_phy_apic_id, h_phy_apic_id; + struct svm_avic_phy_ait_entry *entry, new_entry; + struct vcpu_svm *svm = to_svm(vcpu); + phys_addr_t pa = PFN_PHYS(page_to_pfn(svm->avic_bk_page)); + + if (!avic) + return 0; + + /* Note: APIC ID = 0xff is used for broadcast. + * APIC ID > 0xff is reserved. + */ + g_phy_apic_id = vcpu->vcpu_id; + h_phy_apic_id = __default_cpu_present_to_apicid(vcpu->cpu); + + if ((g_phy_apic_id >= AVIC_PHY_APIC_ID_MAX) || + (h_phy_apic_id >= AVIC_PHY_APIC_ID_MAX)) + return -EINVAL; + + entry = avic_get_phy_ait_entry(vcpu, g_phy_apic_id); + if (!entry) + return -EINVAL; + + if (is_run) { + /** + * Handle vcpu unblocking after HLT + */ + new_entry = READ_ONCE(*entry); + new_entry.is_running = is_run; + WRITE_ONCE(*entry, new_entry); + + ret = avic_update_iommu(vcpu, h_phy_apic_id, pa, is_run); + } else { + /** + * Handle vcpu blocking due to HLT + */ + ret = avic_update_iommu(vcpu, h_phy_apic_id, pa, is_run); + + new_entry = READ_ONCE(*entry); + new_entry.is_running = is_run; + WRITE_ONCE(*entry, new_entry); + } + + return ret; +} + static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) { struct vcpu_svm *svm = to_svm(vcpu); @@ -1648,6 +1790,8 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu) /* This assumes that the kernel never uses MSR_TSC_AUX */ if (static_cpu_has(X86_FEATURE_RDTSCP)) wrmsrl(MSR_TSC_AUX, svm->tsc_aux); + + avic_vcpu_load(vcpu, cpu, true); } static void svm_vcpu_put(struct kvm_vcpu *vcpu) @@ -1655,6 +1799,8 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu) struct vcpu_svm *svm = to_svm(vcpu); int i; + avic_vcpu_load(vcpu, 0, false); + ++vcpu->stat.host_state_reload; kvm_load_ldt(svm->host.ldt); #ifdef CONFIG_X86_64 -- 1.9.1
