diff options
Diffstat (limited to 'arch/x86/hyperv/hv_vtl.c')
| -rw-r--r-- | arch/x86/hyperv/hv_vtl.c | 101 |
1 files changed, 51 insertions, 50 deletions
diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c index 04775346369c..042e8712d8de 100644 --- a/arch/x86/hyperv/hv_vtl.c +++ b/arch/x86/hyperv/hv_vtl.c @@ -11,7 +11,9 @@ #include <asm/desc.h> #include <asm/i8259.h> #include <asm/mshyperv.h> +#include <asm/msr.h> #include <asm/realmode.h> +#include <asm/reboot.h> #include <../kernel/smpboot.h> extern struct boot_params boot_params; @@ -22,14 +24,50 @@ static bool __init hv_vtl_msi_ext_dest_id(void) return true; } +/* + * The `native_machine_emergency_restart` function from `reboot.c` writes + * to the physical address 0x472 to indicate the type of reboot for the + * firmware. We cannot have that in VSM as the memory composition might + * be more generic, and such write effectively corrupts the memory thus + * making diagnostics harder at the very least. + */ +static void __noreturn hv_vtl_emergency_restart(void) +{ + /* + * Cause a triple fault and the immediate reset. Here the code does not run + * on the top of any firmware, whereby cannot reach out to its services. + * The inifinite loop is for the improbable case that the triple fault does + * not work and have to preserve the state intact for debugging. + */ + for (;;) { + idt_invalidate(); + __asm__ __volatile__("int3"); + } +} + +/* + * The only way to restart in the VTL mode is to triple fault as the kernel runs + * as firmware. + */ +static void __noreturn hv_vtl_restart(char __maybe_unused *cmd) +{ + hv_vtl_emergency_restart(); +} + void __init hv_vtl_init_platform(void) { - pr_info("Linux runs in Hyper-V Virtual Trust Level\n"); + /* + * This function is a no-op if the VTL mode is not enabled. + * If it is, this function runs if and only the kernel boots in + * VTL2 which the x86 hv initialization path makes sure of. + */ + pr_info("Linux runs in Hyper-V Virtual Trust Level %d\n", ms_hyperv.vtl); x86_platform.realmode_reserve = x86_init_noop; x86_platform.realmode_init = x86_init_noop; x86_init.irqs.pre_vector_init = x86_init_noop; x86_init.timers.timer_init = x86_init_noop; + x86_init.resources.probe_roms = x86_init_noop; /* Avoid searching for BIOS MP tables */ x86_init.mpparse.find_mptable = x86_init_noop; @@ -117,11 +155,11 @@ static int hv_vtl_bringup_vcpu(u32 target_vp_index, int cpu, u64 eip_ignored) input->vp_context.rip = rip; input->vp_context.rsp = rsp; input->vp_context.rflags = 0x0000000000000002; - input->vp_context.efer = __rdmsr(MSR_EFER); + input->vp_context.efer = native_rdmsrq(MSR_EFER); input->vp_context.cr0 = native_read_cr0(); input->vp_context.cr3 = __native_read_cr3(); input->vp_context.cr4 = native_read_cr4(); - input->vp_context.msr_cr_pat = __rdmsr(MSR_IA32_CR_PAT); + input->vp_context.msr_cr_pat = native_rdmsrq(MSR_IA32_CR_PAT); input->vp_context.idtr.limit = idt_ptr.size; input->vp_context.idtr.base = idt_ptr.address; input->vp_context.gdtr.limit = gdt_ptr.size; @@ -174,67 +212,30 @@ free_lock: return ret; } -static int hv_vtl_apicid_to_vp_id(u32 apic_id) -{ - u64 control; - u64 status; - unsigned long irq_flags; - struct hv_get_vp_from_apic_id_in *input; - u32 *output, ret; - - local_irq_save(irq_flags); - - input = *this_cpu_ptr(hyperv_pcpu_input_arg); - memset(input, 0, sizeof(*input)); - input->partition_id = HV_PARTITION_ID_SELF; - input->apic_ids[0] = apic_id; - - output = (u32 *)input; - - control = HV_HYPERCALL_REP_COMP_1 | HVCALL_GET_VP_ID_FROM_APIC_ID; - status = hv_do_hypercall(control, input, output); - ret = output[0]; - - local_irq_restore(irq_flags); - - if (!hv_result_success(status)) { - pr_err("failed to get vp id from apic id %d, status %#llx\n", - apic_id, status); - return -EINVAL; - } - - return ret; -} - -static int hv_vtl_wakeup_secondary_cpu(u32 apicid, unsigned long start_eip) +static int hv_vtl_wakeup_secondary_cpu(u32 apicid, unsigned long start_eip, unsigned int cpu) { - int vp_id, cpu; - - /* Find the logical CPU for the APIC ID */ - for_each_present_cpu(cpu) { - if (arch_match_cpu_phys_id(cpu, apicid)) - break; - } - if (cpu >= nr_cpu_ids) - return -EINVAL; + int vp_index; pr_debug("Bringing up CPU with APIC ID %d in VTL2...\n", apicid); - vp_id = hv_vtl_apicid_to_vp_id(apicid); + vp_index = hv_apicid_to_vp_index(apicid); - if (vp_id < 0) { + if (vp_index < 0) { pr_err("Couldn't find CPU with APIC ID %d\n", apicid); return -EINVAL; } - if (vp_id > ms_hyperv.max_vp_index) { - pr_err("Invalid CPU id %d for APIC ID %d\n", vp_id, apicid); + if (vp_index > ms_hyperv.max_vp_index) { + pr_err("Invalid CPU id %d for APIC ID %d\n", vp_index, apicid); return -EINVAL; } - return hv_vtl_bringup_vcpu(vp_id, cpu, start_eip); + return hv_vtl_bringup_vcpu(vp_index, cpu, start_eip); } int __init hv_vtl_early_init(void) { + machine_ops.emergency_restart = hv_vtl_emergency_restart; + machine_ops.restart = hv_vtl_restart; + /* * `boot_cpu_has` returns the runtime feature support, * and here is the earliest it can be used. |