extern struct { char _entry[32]; } hypercall_page[];
+void xen_hypercall_func(void);
+DECLARE_STATIC_CALL(xen_hypercall, xen_hypercall_func);
+
#define __HYPERCALL "call hypercall_page+%c[offset]"
#define __HYPERCALL_ENTRY(x) \
[offset] "i" (__HYPERVISOR_##x * sizeof(hypercall_page[0]))
#include <linux/console.h>
#include <linux/cpu.h>
+#include <linux/instrumentation.h>
#include <linux/kexec.h>
#include <linux/memblock.h>
#include <linux/slab.h>
EXPORT_SYMBOL_GPL(hypercall_page);
+DEFINE_STATIC_CALL(xen_hypercall, xen_hypercall_hvm);
+EXPORT_STATIC_CALL_TRAMP(xen_hypercall);
+
/*
* Pointer to the xen_vcpu_info structure or
* &HYPERVISOR_shared_info->vcpu_info[cpu]. See xen_hvm_init_shared_info
*/
struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info;
+static __ref void xen_get_vendor(void)
+{
+ init_cpu_devs();
+ cpu_detect(&boot_cpu_data);
+ get_cpu_vendor(&boot_cpu_data);
+}
+
+void xen_hypercall_setfunc(void)
+{
+ if (static_call_query(xen_hypercall) != xen_hypercall_hvm)
+ return;
+
+ if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
+ boot_cpu_data.x86_vendor == X86_VENDOR_HYGON))
+ static_call_update(xen_hypercall, xen_hypercall_amd);
+ else
+ static_call_update(xen_hypercall, xen_hypercall_intel);
+}
+
+/*
+ * Evaluate processor vendor in order to select the correct hypercall
+ * function for HVM/PVH guests.
+ * Might be called very early in boot before vendor has been set by
+ * early_cpu_init().
+ */
+noinstr void *__xen_hypercall_setfunc(void)
+{
+ void (*func)(void);
+
+ /*
+ * Xen is supported only on CPUs with CPUID, so testing for
+ * X86_FEATURE_CPUID is a test for early_cpu_init() having been
+ * run.
+ *
+ * Note that __xen_hypercall_setfunc() is noinstr only due to a nasty
+ * dependency chain: it is being called via the xen_hypercall static
+ * call when running as a PVH or HVM guest. Hypercalls need to be
+ * noinstr due to PV guests using hypercalls in noinstr code. So we
+ * can safely tag the function body as "instrumentation ok", since
+ * the PV guest requirement is not of interest here (xen_get_vendor()
+ * calls noinstr functions, and static_call_update_early() might do
+ * so, too).
+ */
+ instrumentation_begin();
+
+ if (!boot_cpu_has(X86_FEATURE_CPUID))
+ xen_get_vendor();
+
+ if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
+ boot_cpu_data.x86_vendor == X86_VENDOR_HYGON))
+ func = xen_hypercall_amd;
+ else
+ func = xen_hypercall_intel;
+
+ static_call_update_early(xen_hypercall, func);
+
+ instrumentation_end();
+
+ return func;
+}
+
static int xen_cpu_up_online(unsigned int cpu)
{
xen_init_lock_cpu(cpu);
if (xen_pv_domain())
return 0;
+ /* Set correct hypercall function. */
+ if (xen_domain)
+ xen_hypercall_setfunc();
+
if (xen_pvh_domain() && nopv) {
/* Guest booting via the Xen-PVH boot entry goes here */
pr_info("\"nopv\" parameter is ignored in PVH guest\n");
xen_domain_type = XEN_PV_DOMAIN;
xen_start_flags = xen_start_info->flags;
+ /* Interrupts are guaranteed to be off initially. */
+ early_boot_irqs_disabled = true;
+ static_call_update_early(xen_hypercall, xen_hypercall_pv);
xen_setup_features();
WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_pv, xen_cpu_dead_pv));
local_irq_disable();
- early_boot_irqs_disabled = true;
xen_raw_console_write("mapping kernel into physical memory\n");
xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base,
#include <linux/init.h>
#include <linux/linkage.h>
+#include <linux/objtool.h>
#include <../entry/calling.h>
.pushsection .noinstr.text, "ax"
+/*
+ * PV hypercall interface to the hypervisor.
+ *
+ * Called via inline asm(), so better preserve %rcx and %r11.
+ *
+ * Input:
+ * %eax: hypercall number
+ * %rdi, %rsi, %rdx, %r10, %r8: args 1..5 for the hypercall
+ * Output: %rax
+ */
+SYM_FUNC_START(xen_hypercall_pv)
+ ANNOTATE_NOENDBR
+ push %rcx
+ push %r11
+ UNWIND_HINT_SAVE
+ syscall
+ UNWIND_HINT_RESTORE
+ pop %r11
+ pop %rcx
+ RET
+SYM_FUNC_END(xen_hypercall_pv)
+
/*
* Disabling events is simply a matter of making the event mask
* non-zero.
#include <linux/elfnote.h>
#include <linux/init.h>
+#include <linux/instrumentation.h>
#include <asm/boot.h>
#include <asm/asm.h>
+#include <asm/frame.h>
#include <asm/msr.h>
#include <asm/page_types.h>
#include <asm/percpu.h>
#endif
#endif
+ .pushsection .noinstr.text, "ax"
+/*
+ * Xen hypercall interface to the hypervisor.
+ *
+ * Input:
+ * %eax: hypercall number
+ * 32-bit:
+ * %ebx, %ecx, %edx, %esi, %edi: args 1..5 for the hypercall
+ * 64-bit:
+ * %rdi, %rsi, %rdx, %r10, %r8: args 1..5 for the hypercall
+ * Output: %[er]ax
+ */
+SYM_FUNC_START(xen_hypercall_hvm)
+ ENDBR
+ FRAME_BEGIN
+ /* Save all relevant registers (caller save and arguments). */
+#ifdef CONFIG_X86_32
+ push %eax
+ push %ebx
+ push %ecx
+ push %edx
+ push %esi
+ push %edi
+#else
+ push %rax
+ push %rcx
+ push %rdx
+ push %rdi
+ push %rsi
+ push %r11
+ push %r10
+ push %r9
+ push %r8
+#ifdef CONFIG_FRAME_POINTER
+ pushq $0 /* Dummy push for stack alignment. */
+#endif
+#endif
+ /* Set the vendor specific function. */
+ call __xen_hypercall_setfunc
+ /* Set ZF = 1 if AMD, Restore saved registers. */
+#ifdef CONFIG_X86_32
+ lea xen_hypercall_amd, %ebx
+ cmp %eax, %ebx
+ pop %edi
+ pop %esi
+ pop %edx
+ pop %ecx
+ pop %ebx
+ pop %eax
+#else
+ lea xen_hypercall_amd(%rip), %rbx
+ cmp %rax, %rbx
+#ifdef CONFIG_FRAME_POINTER
+ pop %rax /* Dummy pop. */
+#endif
+ pop %r8
+ pop %r9
+ pop %r10
+ pop %r11
+ pop %rsi
+ pop %rdi
+ pop %rdx
+ pop %rcx
+ pop %rax
+#endif
+ /* Use correct hypercall function. */
+ jz xen_hypercall_amd
+ jmp xen_hypercall_intel
+SYM_FUNC_END(xen_hypercall_hvm)
+
+SYM_FUNC_START(xen_hypercall_amd)
+ vmmcall
+ RET
+SYM_FUNC_END(xen_hypercall_amd)
+
+SYM_FUNC_START(xen_hypercall_intel)
+ vmcall
+ RET
+SYM_FUNC_END(xen_hypercall_intel)
+ .popsection
+
ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS, .asciz "linux")
ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION, .asciz "2.6")
ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION, .asciz "xen-3.0")
static inline void xen_smp_count_cpus(void) { }
#endif /* CONFIG_SMP */
+#ifdef CONFIG_XEN_PV
+void xen_hypercall_pv(void);
+#endif
+void xen_hypercall_hvm(void);
+void xen_hypercall_amd(void);
+void xen_hypercall_intel(void);
+void xen_hypercall_setfunc(void);
+void *__xen_hypercall_setfunc(void);
+
#endif /* XEN_OPS_H */
projects / users / dwmw2 / linux.git / commitdiff