diff options
Diffstat (limited to 'arch/x86/xen/pmu.c')
| -rw-r--r-- | arch/x86/xen/pmu.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c new file mode 100644 index 0000000..1d1ae1b --- /dev/null +++ b/arch/x86/xen/pmu.c @@ -0,0 +1,170 @@ +#include <linux/types.h> +#include <linux/interrupt.h> + +#include <asm/xen/hypercall.h> +#include <xen/page.h> +#include <xen/interface/xen.h> +#include <xen/interface/vcpu.h> +#include <xen/interface/xenpmu.h> + +#include "xen-ops.h" +#include "pmu.h" + +/* x86_pmu.handle_irq definition */ +#include "../kernel/cpu/perf_event.h" + + +/* Shared page between hypervisor and domain */ +static DEFINE_PER_CPU(struct xen_pmu_data *, xenpmu_shared); +#define get_xenpmu_data() per_cpu(xenpmu_shared, smp_processor_id()) + +/* perf callbacks */ +static int xen_is_in_guest(void) +{ + const struct xen_pmu_data *xenpmu_data = get_xenpmu_data(); + + if (!xenpmu_data) { + pr_warn_once("%s: pmudata not initialized\n", __func__); + return 0; + } + + if (!xen_initial_domain() || (xenpmu_data->domain_id >= DOMID_SELF)) + return 0; + + return 1; +} + +static int xen_is_user_mode(void) +{ + const struct xen_pmu_data *xenpmu_data = get_xenpmu_data(); + + if (!xenpmu_data) { + pr_warn_once("%s: pmudata not initialized\n", __func__); + return 0; + } + + if (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_PV) + return (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_USER); + else + return !!(xenpmu_data->pmu.r.regs.cpl & 3); +} + +static unsigned long xen_get_guest_ip(void) +{ + const struct xen_pmu_data *xenpmu_data = get_xenpmu_data(); + + if (!xenpmu_data) { + pr_warn_once("%s: pmudata not initialized\n", __func__); + return 0; + } + + return xenpmu_data->pmu.r.regs.ip; +} + +static struct perf_guest_info_callbacks xen_guest_cbs = { + .is_in_guest = xen_is_in_guest, + .is_user_mode = xen_is_user_mode, + .get_guest_ip = xen_get_guest_ip, +}; + +/* Convert registers from Xen's format to Linux' */ +static void xen_convert_regs(const struct xen_pmu_regs *xen_regs, + struct pt_regs *regs, uint64_t pmu_flags) +{ + regs->ip = xen_regs->ip; + regs->cs = xen_regs->cs; + regs->sp = xen_regs->sp; + + if (pmu_flags & PMU_SAMPLE_PV) { + if (pmu_flags & PMU_SAMPLE_USER) + regs->cs |= 3; + else + regs->cs &= ~3; + } else { + if (xen_regs->cpl) + regs->cs |= 3; + else + regs->cs &= ~3; + } +} + +irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id) +{ + int ret = IRQ_NONE; + struct pt_regs regs; + const struct xen_pmu_data *xenpmu_data = get_xenpmu_data(); + + if (!xenpmu_data) { + pr_warn_once("%s: pmudata not initialized\n", __func__); + return ret; + } + + xen_convert_regs(&xenpmu_data->pmu.r.regs, ®s, + xenpmu_data->pmu.pmu_flags); + if (x86_pmu.handle_irq(®s)) + ret = IRQ_HANDLED; + + return ret; +} + +bool is_xen_pmu(int cpu) +{ + return (per_cpu(xenpmu_shared, cpu) != NULL); +} + +void xen_pmu_init(int cpu) +{ + int err; + struct xen_pmu_params xp; + unsigned long pfn; + struct xen_pmu_data *xenpmu_data; + + BUILD_BUG_ON(sizeof(struct xen_pmu_data) > PAGE_SIZE); + + if (xen_hvm_domain()) + return; + + xenpmu_data = (struct xen_pmu_data *)get_zeroed_page(GFP_KERNEL); + if (!xenpmu_data) { + pr_err("VPMU init: No memory\n"); + return; + } + pfn = virt_to_pfn(xenpmu_data); + + xp.val = pfn_to_mfn(pfn); + xp.vcpu = cpu; + xp.version.maj = XENPMU_VER_MAJ; + xp.version.min = XENPMU_VER_MIN; + err = HYPERVISOR_xenpmu_op(XENPMU_init, &xp); + if (err) + goto fail; + + per_cpu(xenpmu_shared, cpu) = xenpmu_data; + + if (cpu == 0) + perf_register_guest_info_callbacks(&xen_guest_cbs); + + return; + +fail: + pr_warn_once("Could not initialize VPMU for cpu %d, error %d\n", + cpu, err); + free_pages((unsigned long)xenpmu_data, 0); +} + +void xen_pmu_finish(int cpu) +{ + struct xen_pmu_params xp; + + if (xen_hvm_domain()) + return; + + xp.vcpu = cpu; + xp.version.maj = XENPMU_VER_MAJ; + xp.version.min = XENPMU_VER_MIN; + + (void)HYPERVISOR_xenpmu_op(XENPMU_finish, &xp); + + free_pages((unsigned long)per_cpu(xenpmu_shared, cpu), 0); + per_cpu(xenpmu_shared, cpu) = NULL; +} |