Add support for handling INCOMPLET_IPI #VC exception handling for Secure AVIC guests. This allows sending cross-vCPU IPI, using all destination shorthands (broadcast, fixed) and destination modes (logical/physical) between Secure AVIC enabled vCPUs. In addition, cross-vCPU NMI using APIC_ICR writes are supported.
Signed-off-by: Neeraj Upadhyay <[email protected]> --- tools/testing/selftests/kvm/lib/x86/savic.c | 112 ++++++++++++++++++++ 1 file changed, 112 insertions(+) diff --git a/tools/testing/selftests/kvm/lib/x86/savic.c b/tools/testing/selftests/kvm/lib/x86/savic.c index 141d31637e51..8259f7521e73 100644 --- a/tools/testing/selftests/kvm/lib/x86/savic.c +++ b/tools/testing/selftests/kvm/lib/x86/savic.c @@ -43,6 +43,12 @@ enum lapic_lvt_entry { #define MSR_AMD64_SECURE_AVIC_ALLOWED_NMI_BIT 1 #define SVM_EXIT_AVIC_UNACCELERATED_ACCESS 0x402 +#define SVM_EXIT_AVIC_INCOMPLETE_IPI 0x401 + +#define REG_OFF(VEC) (VEC / 32 * 16) +#define VEC_POS(VEC) (VEC % 32) + +#define SAVIC_NMI_REQ_OFFSET 0x278 /* * Initial pool of guest apic backing page. @@ -336,6 +342,105 @@ static void handle_savic_unaccel_access(struct ex_regs *regs) } } +static void send_ipi(int cpu, int vector, bool nmi) +{ + struct guest_apic_page *apic_page; + + apic_page = &apic_page_pool->guest_apic_page[cpu]; + + if (nmi) + savic_write_reg(apic_page, SAVIC_NMI_REQ_OFFSET, 1); + else + savic_write_reg(apic_page, APIC_IRR + REG_OFF(vector), BIT(VEC_POS(vector))); +} + +static bool is_cpu_present(int cpu) +{ + struct guest_apic_page *apic_page; + + if (cpu >= KVM_MAX_VCPUS) + return false; + + apic_page = &apic_page_pool->guest_apic_page[cpu]; + + return savic_read_reg(apic_page, APIC_ID) != 0; +} + +static void savic_send_ipi_all_but(int vector, bool nmi) +{ + int cpu; + int mycpu = x2apic_read_reg(APIC_ID); + + for (cpu = 0; cpu < KVM_MAX_VCPUS; cpu++) { + if (cpu == mycpu) + continue; + if (!(cpu == 0 || is_cpu_present(cpu))) + break; + send_ipi(cpu, vector, nmi); + } +} + +static bool ipi_match_dest(uint32_t dest, bool logical, int dest_cpu) +{ + struct guest_apic_page *apic_page; + + apic_page = &apic_page_pool->guest_apic_page[dest_cpu]; + uint32_t ldr; + + if (logical) { + ldr = savic_read_reg(apic_page, APIC_LDR); + return ((ldr >> 16) == (dest >> 16)) && + (ldr & dest & 0xffff) != 0; + } else { + return dest == savic_read_reg(apic_page, APIC_ID); + } +} + +static void savic_send_ipi_target(uint32_t dest, int vector, bool logical, + bool nmi) +{ + int cpu; + int mycpu = x2apic_read_reg(APIC_ID); + + for (cpu = 0; cpu < KVM_MAX_VCPUS; cpu++) { + if (cpu == mycpu) { + continue; + } + if (!(cpu == 0 || is_cpu_present(cpu))) + break; + if (ipi_match_dest(dest, logical, cpu)) + send_ipi(cpu, vector, nmi); + } +} + +static void savic_handle_icr_write(uint64_t icr_data) +{ + int dsh = icr_data & APIC_DEST_ALLBUT; + int vector = icr_data & APIC_VECTOR_MASK; + bool logical = icr_data & APIC_DEST_LOGICAL; + bool nmi = (icr_data & APIC_DM_FIXED_MASK) == APIC_DM_NMI; + uint64_t self_icr_data = APIC_DEST_SELF | APIC_INT_ASSERT | vector; + + if (nmi) + self_icr_data |= APIC_DM_NMI; + + switch (dsh) { + case APIC_DEST_ALLINC: + savic_send_ipi_all_but(vector, nmi); + savic_hv_write_reg(APIC_ICR, icr_data); + x2apic_write_reg(APIC_ICR, self_icr_data); + break; + case APIC_DEST_ALLBUT: + savic_send_ipi_all_but(vector, nmi); + savic_hv_write_reg(APIC_ICR, icr_data); + break; + default: + savic_send_ipi_target(icr_data >> 32, vector, logical, nmi); + savic_hv_write_reg(APIC_ICR, icr_data); + break; + } +} + void savic_vc_handler(struct ex_regs *regs) { uint64_t exit_code = regs->error_code; @@ -344,6 +449,13 @@ void savic_vc_handler(struct ex_regs *regs) case SVM_EXIT_AVIC_UNACCELERATED_ACCESS: handle_savic_unaccel_access(regs); break; + case SVM_EXIT_AVIC_INCOMPLETE_IPI: + uint64_t icr_data = regs->rax | (regs->rdx << 32); + uint32_t reg = (regs->rcx - APIC_BASE_MSR) << 4; + + GUEST_ASSERT(reg == APIC_ICR); + savic_handle_icr_write(icr_data); + break; default: sev_es_vc_handler(regs); break; -- 2.34.1
