x86/vmexit.c

#include "libcflat.h"
#include "acpi.h"
#include "smp.h"
#include "vmalloc.h"
#include "pci.h"
#include "x86/vm.h"
#include "x86/desc.h"
#include "x86/apic.h"
#include "x86/isr.h"

#define IPI_TEST_VECTOR	0xb0

struct test {
	void (*func)(void);
	const char *name;
	int (*valid)(void);
	int parallel;
	bool (*next)(struct test *);
};

#define GOAL (1ull << 30)

static int nr_cpus;
static u64 cr4_shadow;

static void cpuid_test(void)
{
	asm volatile ("push %%"R "bx; cpuid; pop %%"R "bx"
		      : : : "eax", "ecx", "edx");
}

static void vmcall(void)
{
	unsigned long a = 0, b, c, d;

	asm volatile ("vmcall" : "+a"(a), "=b"(b), "=c"(c), "=d"(d));
}

#define MSR_EFER 0xc0000080
#define EFER_NX_MASK            (1ull << 11)

#ifdef __x86_64__
static void mov_from_cr8(void)
{
	unsigned long cr8;

	asm volatile ("mov %%cr8, %0" : "=r"(cr8));
}

static void mov_to_cr8(void)
{
	unsigned long cr8 = 0;

	asm volatile ("mov %0, %%cr8" : : "r"(cr8));
}
#endif

static int is_smp(void)
{
	return cpu_count() > 1;
}

static void nop(void *junk)
{
}

volatile int x = 0;
volatile uint64_t tsc_eoi = 0;
volatile uint64_t tsc_ipi = 0;

static void self_ipi_isr(isr_regs_t *regs)
{
	x++;
	uint64_t start = rdtsc();
	eoi();
	tsc_eoi += rdtsc() - start;
}

static void x2apic_self_ipi(int vec)
{
	uint64_t start = rdtsc();
	wrmsr(0x83f, vec);
	tsc_ipi += rdtsc() - start;
}

static void apic_self_ipi(int vec)
{
	uint64_t start = rdtsc();
        apic_icr_write(APIC_INT_ASSERT | APIC_DEST_SELF | APIC_DEST_PHYSICAL |
		       APIC_DM_FIXED | IPI_TEST_VECTOR, vec);
	tsc_ipi += rdtsc() - start;
}

static void self_ipi_sti_nop(void)
{
	x = 0;
	cli();
	apic_self_ipi(IPI_TEST_VECTOR);
	asm volatile("sti; nop");
	if (x != 1) printf("%d", x);
}

static void self_ipi_sti_hlt(void)
{
	x = 0;
	cli();
	apic_self_ipi(IPI_TEST_VECTOR);
	safe_halt();
	if (x != 1) printf("%d", x);
}

static void self_ipi_tpr(void)
{
	x = 0;
	apic_set_tpr(0x0f);
	apic_self_ipi(IPI_TEST_VECTOR);
	apic_set_tpr(0x00);
	asm volatile("nop");
	if (x != 1) printf("%d", x);
}

static void self_ipi_tpr_sti_nop(void)
{
	x = 0;
	cli();
	apic_set_tpr(0x0f);
	apic_self_ipi(IPI_TEST_VECTOR);
	apic_set_tpr(0x00);
	asm volatile("sti; nop");
	if (x != 1) printf("%d", x);
}

static void self_ipi_tpr_sti_hlt(void)
{
	x = 0;
	cli();
	apic_set_tpr(0x0f);
	apic_self_ipi(IPI_TEST_VECTOR);
	apic_set_tpr(0x00);
	safe_halt();
	if (x != 1) printf("%d", x);
}

static int is_x2apic(void)
{
    return rdmsr(MSR_IA32_APICBASE) & APIC_EXTD;
}

static void x2apic_self_ipi_sti_nop(void)
{
	cli();
	x2apic_self_ipi(IPI_TEST_VECTOR);
	asm volatile("sti; nop");
}

static void x2apic_self_ipi_sti_hlt(void)
{
	cli();
	x2apic_self_ipi(IPI_TEST_VECTOR);
	safe_halt();
}

static void x2apic_self_ipi_tpr(void)
{
	apic_set_tpr(0x0f);
	x2apic_self_ipi(IPI_TEST_VECTOR);
	apic_set_tpr(0x00);
	asm volatile("nop");
}

static void x2apic_self_ipi_tpr_sti_nop(void)
{
	cli();
	apic_set_tpr(0x0f);
	x2apic_self_ipi(IPI_TEST_VECTOR);
	apic_set_tpr(0x00);
	asm volatile("sti; nop");
}

static void x2apic_self_ipi_tpr_sti_hlt(void)
{
	cli();
	apic_set_tpr(0x0f);
	x2apic_self_ipi(IPI_TEST_VECTOR);
	apic_set_tpr(0x00);
	safe_halt();
}

static void ipi(void)
{
	uint64_t start = rdtsc();
	on_cpu(1, nop, 0);
	tsc_ipi += rdtsc() - start;
}

static void ipi_halt(void)
{
	unsigned long long t;

	on_cpu(1, nop, 0);
	t = rdtsc() + 2000;
	while (rdtsc() < t)
		;
}

int pm_tmr_blk;
static void inl_pmtimer(void)
{
    if (!pm_tmr_blk) {
	struct acpi_table_fadt *fadt;

	fadt = find_acpi_table_addr(FACP_SIGNATURE);
	pm_tmr_blk = fadt->pm_tmr_blk;
	printf("PM timer port is %x\n", pm_tmr_blk);
    }
    inl(pm_tmr_blk);
}

static void inl_nop_qemu(void)
{
    inl(0x1234);
}

static void inl_nop_kernel(void)
{
    inb(0x4d0);
}

static void outl_elcr_kernel(void)
{
    outb(0, 0x4d0);
}

static void mov_dr(void)
{
    asm volatile("mov %0, %%dr7" : : "r" (0x400L));
}

static void ple_round_robin(void)
{
	struct counter {
		volatile int n1;
		int n2;
	} __attribute__((aligned(64)));
	static struct counter counters[64] = { { -1, 0 } };
	int me = smp_id();
	int you;
	volatile struct counter *p = &counters[me];

	while (p->n1 == p->n2)
		asm volatile ("pause");

	p->n2 = p->n1;
	you = me + 1;
	if (you == nr_cpus)
		you = 0;
	++counters[you].n1;
}

static void rd_tsc_adjust_msr(void)
{
	rdmsr(MSR_IA32_TSC_ADJUST);
}

static void wr_tsc_adjust_msr(void)
{
	wrmsr(MSR_IA32_TSC_ADJUST, 0x0);
}

static void wr_kernel_gs_base(void)
{
	wrmsr(MSR_KERNEL_GS_BASE, 0x0);
}

static struct pci_test {
	unsigned iobar;
	unsigned ioport;
	volatile void *memaddr;
	volatile void *mem;
	int test_idx;
	uint32_t data;
	uint32_t offset;
} pci_test = {
	.test_idx = -1
};

static void pci_mem_testb(void)
{
	*(volatile uint8_t *)pci_test.mem = pci_test.data;
}

static void pci_mem_testw(void)
{
	*(volatile uint16_t *)pci_test.mem = pci_test.data;
}

static void pci_mem_testl(void)
{
	*(volatile uint32_t *)pci_test.mem = pci_test.data;
}

static void pci_io_testb(void)
{
	outb(pci_test.data, pci_test.ioport);
}

static void pci_io_testw(void)
{
	outw(pci_test.data, pci_test.ioport);
}

static void pci_io_testl(void)
{
	outl(pci_test.data, pci_test.ioport);
}

static uint8_t ioreadb(unsigned long addr, bool io)
{
	if (io) {
		return inb(addr);
	} else {
		return *(volatile uint8_t *)addr;
	}
}

static uint32_t ioreadl(unsigned long addr, bool io)
{
	/* Note: assumes little endian */
	if (io) {
		return inl(addr);
	} else {
		return *(volatile uint32_t *)addr;
	}
}

static void iowriteb(unsigned long addr, uint8_t data, bool io)
{
	if (io) {
		outb(data, addr);
	} else {
		*(volatile uint8_t *)addr = data;
	}
}

static bool pci_next(struct test *test, unsigned long addr, bool io)
{
	int i;
	uint8_t width;

	if (!pci_test.memaddr) {
		test->func = NULL;
		return true;
	}
	pci_test.test_idx++;
	iowriteb(addr + offsetof(struct pci_test_dev_hdr, test),
		 pci_test.test_idx, io);
	width = ioreadb(addr + offsetof(struct pci_test_dev_hdr, width),
			io);
	switch (width) {
		case 1:
			test->func = io ? pci_io_testb : pci_mem_testb;
			break;
		case 2:
			test->func = io ? pci_io_testw : pci_mem_testw;
			break;
		case 4:
			test->func = io ? pci_io_testl : pci_mem_testl;
			break;
		default:
			/* Reset index for purposes of the next test */
			pci_test.test_idx = -1;
			test->func = NULL;
			return false;
	}
	pci_test.data = ioreadl(addr + offsetof(struct pci_test_dev_hdr, data),
				io);
	pci_test.offset = ioreadl(addr + offsetof(struct pci_test_dev_hdr,
						  offset), io);
	for (i = 0; i < pci_test.offset; ++i) {
		char c = ioreadb(addr + offsetof(struct pci_test_dev_hdr,
						 name) + i, io);
		if (!c) {
			break;
		}
		printf("%c",c);
	}
	printf(":");
	return true;
}

static bool pci_mem_next(struct test *test)
{
	bool ret;
	ret = pci_next(test, ((unsigned long)pci_test.memaddr), false);
	if (ret) {
		pci_test.mem = pci_test.memaddr + pci_test.offset;
	}
	return ret;
}

static bool pci_io_next(struct test *test)
{
	bool ret;
	ret = pci_next(test, ((unsigned long)pci_test.iobar), true);
	if (ret) {
		pci_test.ioport = pci_test.iobar + pci_test.offset;
	}
	return ret;
}

static int has_tscdeadline(void)
{
    uint32_t lvtt;

    if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
        lvtt = APIC_LVT_TIMER_TSCDEADLINE | IPI_TEST_VECTOR;
        apic_write(APIC_LVTT, lvtt);
        return 1;
    } else {
        return 0;
    }
}

static void tscdeadline_immed(void)
{
	wrmsr(MSR_IA32_TSCDEADLINE, rdtsc());
	asm volatile("nop");
}

static void tscdeadline(void)
{
	x = 0;
	wrmsr(MSR_IA32_TSCDEADLINE, rdtsc()+3000);
	while (x == 0) barrier();
}

static void wr_tsx_ctrl_msr(void)
{
	wrmsr(MSR_IA32_TSX_CTRL, 0);
}

static int has_tsx_ctrl(void)
{
	return this_cpu_has(X86_FEATURE_ARCH_CAPABILITIES) &&
	       (rdmsr(MSR_IA32_ARCH_CAPABILITIES) & ARCH_CAP_TSX_CTRL_MSR);
}

static void wr_ibrs_msr(void)
{
	wrmsr(MSR_IA32_SPEC_CTRL, 1);
	wrmsr(MSR_IA32_SPEC_CTRL, 0);
}

static int has_ibpb(void)
{
	return this_cpu_has(X86_FEATURE_SPEC_CTRL) ||
	       this_cpu_has(X86_FEATURE_AMD_IBPB);
}

static int has_spec_ctrl(void)
{
	return this_cpu_has(X86_FEATURE_SPEC_CTRL);
}

static void wr_ibpb_msr(void)
{
	wrmsr(MSR_IA32_PRED_CMD, PRED_CMD_IBPB);
}

static void toggle_cr0_wp(void)
{
	write_cr0(X86_CR0_PE|X86_CR0_PG);
	write_cr0(X86_CR0_PE|X86_CR0_WP|X86_CR0_PG);
}

static void toggle_cr4_pge(void)
{
	write_cr4(cr4_shadow ^ X86_CR4_PGE);
	write_cr4(cr4_shadow);
}

static struct test tests[] = {
	{ cpuid_test, "cpuid", .parallel = 1,  },
	{ vmcall, "vmcall", .parallel = 1, },
#ifdef __x86_64__
	{ mov_from_cr8, "mov_from_cr8", .parallel = 1, },
	{ mov_to_cr8, "mov_to_cr8" , .parallel = 1, },
#endif
	{ inl_pmtimer, "inl_from_pmtimer", .parallel = 1, },
	{ inl_nop_qemu, "inl_from_qemu", .parallel = 1 },
	{ inl_nop_kernel, "inl_from_kernel", .parallel = 1 },
	{ outl_elcr_kernel, "outl_to_kernel", .parallel = 1 },
	{ mov_dr, "mov_dr", .parallel = 1 },
	{ tscdeadline_immed, "tscdeadline_immed", has_tscdeadline, .parallel = 1, },
	{ tscdeadline, "tscdeadline", has_tscdeadline, .parallel = 1, },
	{ self_ipi_sti_nop, "self_ipi_sti_nop", .parallel = 0, },
	{ self_ipi_sti_hlt, "self_ipi_sti_hlt", .parallel = 0, },
	{ self_ipi_tpr, "self_ipi_tpr", .parallel = 0, },
	{ self_ipi_tpr_sti_nop, "self_ipi_tpr_sti_nop", .parallel = 0, },
	{ self_ipi_tpr_sti_hlt, "self_ipi_tpr_sti_hlt", .parallel = 0, },
	{ x2apic_self_ipi_sti_nop, "x2apic_self_ipi_sti_nop", is_x2apic, .parallel = 0, },
	{ x2apic_self_ipi_sti_hlt, "x2apic_self_ipi_sti_hlt", is_x2apic, .parallel = 0, },
	{ x2apic_self_ipi_tpr, "x2apic_self_ipi_tpr", is_x2apic, .parallel = 0, },
	{ x2apic_self_ipi_tpr_sti_nop, "x2apic_self_ipi_tpr_sti_nop", is_x2apic, .parallel = 0, },
	{ x2apic_self_ipi_tpr_sti_hlt, "x2apic_self_ipi_tpr_sti_hlt", is_x2apic, .parallel = 0, },
	{ ipi, "ipi", is_smp, .parallel = 0, },
	{ ipi_halt, "ipi_halt", is_smp, .parallel = 0, },
	{ ple_round_robin, "ple_round_robin", .parallel = 1 },
	{ wr_kernel_gs_base, "wr_kernel_gs_base", .parallel = 1 },
	{ wr_tsx_ctrl_msr, "wr_tsx_ctrl_msr", has_tsx_ctrl, .parallel = 1, },
	{ wr_ibrs_msr, "wr_ibrs_msr", has_spec_ctrl, .parallel = 1 },
	{ wr_ibpb_msr, "wr_ibpb_msr", has_ibpb, .parallel = 1 },
	{ wr_tsc_adjust_msr, "wr_tsc_adjust_msr", .parallel = 1 },
	{ rd_tsc_adjust_msr, "rd_tsc_adjust_msr", .parallel = 1 },
	{ toggle_cr0_wp, "toggle_cr0_wp" , .parallel = 1, },
	{ toggle_cr4_pge, "toggle_cr4_pge" , .parallel = 1, },
	{ NULL, "pci-mem", .parallel = 0, .next = pci_mem_next },
	{ NULL, "pci-io", .parallel = 0, .next = pci_io_next },
};

unsigned iterations;

static void run_test(void *_func)
{
    int i;
    void (*func)(void) = _func;

    for (i = 0; i < iterations; ++i)
        func();
}

static bool do_test(struct test *test)
{
	int i;
	unsigned long long t1, t2;
        void (*func)(void);

        iterations = 32;

        if (test->valid && !test->valid()) {
		printf("%s (skipped)\n", test->name);
		return false;
	}

	if (test->next && !test->next(test)) {
		return false;
	}

	func = test->func;
        if (!func) {
		printf("%s (skipped)\n", test->name);
		return false;
	}

	do {
		tsc_eoi = tsc_ipi = 0;
		iterations *= 2;
		t1 = rdtsc();

		if (!test->parallel) {
			for (i = 0; i < iterations; ++i)
				func();
		} else {
			on_cpus(run_test, func);
		}
		t2 = rdtsc();
	} while ((t2 - t1) < GOAL);
	printf("%s %d\n", test->name, (int)((t2 - t1) / iterations));
	if (tsc_ipi)
		printf("  ipi %s %d\n", test->name, (int)(tsc_ipi / iterations));
	if (tsc_eoi)
		printf("  eoi %s %d\n", test->name, (int)(tsc_eoi / iterations));

	return test->next;
}

static void enable_nx(void *junk)
{
	if (this_cpu_has(X86_FEATURE_NX))
		wrmsr(MSR_EFER, rdmsr(MSR_EFER) | EFER_NX_MASK);
}

static bool test_wanted(struct test *test, char *wanted[], int nwanted)
{
	int i;

	if (!nwanted)
		return true;

	for (i = 0; i < nwanted; ++i)
		if (strcmp(wanted[i], test->name) == 0)
			return true;

	return false;
}

int main(int ac, char **av)
{
	int i;
	unsigned long membar = 0;
	struct pci_dev pcidev;
	int ret;

	setup_vm();
	cr4_shadow = read_cr4();
	handle_irq(IPI_TEST_VECTOR, self_ipi_isr);
	nr_cpus = cpu_count();

	sti();
	on_cpus(enable_nx, NULL);

	ret = pci_find_dev(PCI_VENDOR_ID_REDHAT, PCI_DEVICE_ID_REDHAT_TEST);
	if (ret != PCIDEVADDR_INVALID) {
		pci_dev_init(&pcidev, ret);
		assert(pci_bar_is_memory(&pcidev, PCI_TESTDEV_BAR_MEM));
		assert(!pci_bar_is_memory(&pcidev, PCI_TESTDEV_BAR_IO));
		membar = pcidev.resource[PCI_TESTDEV_BAR_MEM];
		pci_test.memaddr = ioremap(membar, PAGE_SIZE);
		pci_test.iobar = pcidev.resource[PCI_TESTDEV_BAR_IO];
		printf("pci-testdev at %#x membar %lx iobar %x\n",
		       pcidev.bdf, membar, pci_test.iobar);
	}

	for (i = 0; i < ARRAY_SIZE(tests); ++i)
		if (test_wanted(&tests[i], av + 1, ac - 1))
			while (do_test(&tests[i])) {}

	return 0;
}