diff options
| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2008-03-17 16:37:17 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-04-24 23:57:31 +0200 |
| commit | e2a81baf6604a2e08e10c7405b0349106f77c8af (patch) | |
| tree | 3eaf386316be1f499d92fae213493ec3d6b5b576 /arch/x86/xen/setup.c | |
| parent | aa380c82b83252754a8c11bfc92359bd87cbf710 (diff) | |
xen: support sysenter/sysexit if hypervisor does
64-bit Xen supports sysenter for 32-bit guests, so support its
use. (sysenter is faster than int $0x80 in 32-on-64.)
sysexit is still not supported, so we fake it up using iret.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/xen/setup.c')
| -rw-r--r-- | arch/x86/xen/setup.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 2341492bf7a..82517e4a752 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -16,6 +16,7 @@ #include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h> +#include <xen/interface/callback.h> #include <xen/interface/physdev.h> #include <xen/features.h> @@ -68,6 +69,24 @@ static void __init fiddle_vdso(void) *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT; } +void xen_enable_sysenter(void) +{ + int cpu = smp_processor_id(); + extern void xen_sysenter_target(void); + /* Mask events on entry, even though they get enabled immediately */ + static struct callback_register sysenter = { + .type = CALLBACKTYPE_sysenter, + .address = { __KERNEL_CS, (unsigned long)xen_sysenter_target }, + .flags = CALLBACKF_mask_events, + }; + + if (!boot_cpu_has(X86_FEATURE_SEP) || + HYPERVISOR_callback_op(CALLBACKOP_register, &sysenter) != 0) { + clear_cpu_cap(&cpu_data(cpu), X86_FEATURE_SEP); + clear_cpu_cap(&boot_cpu_data, X86_FEATURE_SEP); + } +} + void __init xen_arch_setup(void) { struct physdev_set_iopl set_iopl; @@ -82,6 +101,8 @@ void __init xen_arch_setup(void) HYPERVISOR_set_callbacks(__KERNEL_CS, (unsigned long)xen_hypervisor_callback, __KERNEL_CS, (unsigned long)xen_failsafe_callback); + xen_enable_sysenter(); + set_iopl.iopl = 1; rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); if (rc != 0) |