kernel-fxtec-pro1x/arch/x86/xen/xen-head.S
Mukesh Rathor a2ef5dc2c7 x86/xen: Set EFER.NX and EFER.SCE in PVH guests
This fixes two bugs in PVH guests:

  - Not setting EFER.NX means the NX bit in page table entries is
    ignored on Intel processors and causes reserved bit page faults on
    AMD processors.

  - After the Xen commit 7645640d6ff1 ("x86/PVH: don't set EFER_SCE for
    pvh guest") PVH guests are required to set EFER.SCE to enable the
    SYSCALL instruction.

Secondary VCPUs are started with pagetables with the NX bit set so
EFER.NX must be set before using any stack or data segment.
xen_pvh_cpu_early_init() is the new secondary VCPU entry point that
sets EFER before jumping to cpu_bringup_and_idle().

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-10-06 10:27:47 +01:00

166 lines
4.8 KiB
ArmAsm

/* Xen-specific pieces of head.S, intended to be included in the right
place in head.S */
#ifdef CONFIG_XEN
#include <linux/elfnote.h>
#include <linux/init.h>
#include <asm/boot.h>
#include <asm/asm.h>
#include <asm/page_types.h>
#include <xen/interface/elfnote.h>
#include <xen/interface/features.h>
#include <asm/xen/interface.h>
#ifdef CONFIG_XEN_PVH
#define PVH_FEATURES_STR "|writable_descriptor_tables|auto_translated_physmap|supervisor_mode_kernel"
/* Note the lack of 'hvm_callback_vector'. Older hypervisor will
* balk at this being part of XEN_ELFNOTE_FEATURES, so we put it in
* XEN_ELFNOTE_SUPPORTED_FEATURES which older hypervisors will ignore.
*/
#define PVH_FEATURES ((1 << XENFEAT_writable_page_tables) | \
(1 << XENFEAT_auto_translated_physmap) | \
(1 << XENFEAT_supervisor_mode_kernel) | \
(1 << XENFEAT_hvm_callback_vector))
/* The XENFEAT_writable_page_tables is not stricly neccessary as we set that
* up regardless whether this CONFIG option is enabled or not, but it
* clarifies what the right flags need to be.
*/
#else
#define PVH_FEATURES_STR ""
#define PVH_FEATURES (0)
#endif
__INIT
ENTRY(startup_xen)
cld
#ifdef CONFIG_X86_32
mov %esi,xen_start_info
mov $init_thread_union+THREAD_SIZE,%esp
#else
mov %rsi,xen_start_info
mov $init_thread_union+THREAD_SIZE,%rsp
#endif
jmp xen_start_kernel
__FINIT
#ifdef CONFIG_XEN_PVH
/*
* xen_pvh_early_cpu_init() - early PVH VCPU initialization
* @cpu: this cpu number (%rdi)
* @entry: true if this is a secondary vcpu coming up on this entry
* point, false if this is the boot CPU being initialized for
* the first time (%rsi)
*
* Note: This is called as a function on the boot CPU, and is the entry point
* on the secondary CPU.
*/
ENTRY(xen_pvh_early_cpu_init)
mov %rsi, %r11
/* Gather features to see if NX implemented. */
mov $0x80000001, %eax
cpuid
mov %edx, %esi
mov $MSR_EFER, %ecx
rdmsr
bts $_EFER_SCE, %eax
bt $20, %esi
jnc 1f /* No NX, skip setting it */
bts $_EFER_NX, %eax
1: wrmsr
#ifdef CONFIG_SMP
cmp $0, %r11b
jne cpu_bringup_and_idle
#endif
ret
#endif /* CONFIG_XEN_PVH */
.pushsection .text
.balign PAGE_SIZE
ENTRY(hypercall_page)
#define NEXT_HYPERCALL(x) \
ENTRY(xen_hypercall_##x) \
.skip 32
NEXT_HYPERCALL(set_trap_table)
NEXT_HYPERCALL(mmu_update)
NEXT_HYPERCALL(set_gdt)
NEXT_HYPERCALL(stack_switch)
NEXT_HYPERCALL(set_callbacks)
NEXT_HYPERCALL(fpu_taskswitch)
NEXT_HYPERCALL(sched_op_compat)
NEXT_HYPERCALL(platform_op)
NEXT_HYPERCALL(set_debugreg)
NEXT_HYPERCALL(get_debugreg)
NEXT_HYPERCALL(update_descriptor)
NEXT_HYPERCALL(ni)
NEXT_HYPERCALL(memory_op)
NEXT_HYPERCALL(multicall)
NEXT_HYPERCALL(update_va_mapping)
NEXT_HYPERCALL(set_timer_op)
NEXT_HYPERCALL(event_channel_op_compat)
NEXT_HYPERCALL(xen_version)
NEXT_HYPERCALL(console_io)
NEXT_HYPERCALL(physdev_op_compat)
NEXT_HYPERCALL(grant_table_op)
NEXT_HYPERCALL(vm_assist)
NEXT_HYPERCALL(update_va_mapping_otherdomain)
NEXT_HYPERCALL(iret)
NEXT_HYPERCALL(vcpu_op)
NEXT_HYPERCALL(set_segment_base)
NEXT_HYPERCALL(mmuext_op)
NEXT_HYPERCALL(xsm_op)
NEXT_HYPERCALL(nmi_op)
NEXT_HYPERCALL(sched_op)
NEXT_HYPERCALL(callback_op)
NEXT_HYPERCALL(xenoprof_op)
NEXT_HYPERCALL(event_channel_op)
NEXT_HYPERCALL(physdev_op)
NEXT_HYPERCALL(hvm_op)
NEXT_HYPERCALL(sysctl)
NEXT_HYPERCALL(domctl)
NEXT_HYPERCALL(kexec_op)
NEXT_HYPERCALL(tmem_op) /* 38 */
ENTRY(xen_hypercall_rsvr)
.skip 320
NEXT_HYPERCALL(mca) /* 48 */
NEXT_HYPERCALL(arch_1)
NEXT_HYPERCALL(arch_2)
NEXT_HYPERCALL(arch_3)
NEXT_HYPERCALL(arch_4)
NEXT_HYPERCALL(arch_5)
NEXT_HYPERCALL(arch_6)
.balign PAGE_SIZE
.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")
#ifdef CONFIG_X86_32
ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE, _ASM_PTR __PAGE_OFFSET)
#else
ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE, _ASM_PTR __START_KERNEL_map)
#endif
ELFNOTE(Xen, XEN_ELFNOTE_ENTRY, _ASM_PTR startup_xen)
ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)
ELFNOTE(Xen, XEN_ELFNOTE_FEATURES, .ascii "!writable_page_tables|pae_pgdir_above_4gb"; .asciz PVH_FEATURES_STR)
ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES, .long (PVH_FEATURES) |
(1 << XENFEAT_writable_page_tables) |
(1 << XENFEAT_dom0))
ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE, .asciz "yes")
ELFNOTE(Xen, XEN_ELFNOTE_LOADER, .asciz "generic")
ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
.quad _PAGE_PRESENT; .quad _PAGE_PRESENT)
ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long 1)
ELFNOTE(Xen, XEN_ELFNOTE_MOD_START_PFN, .long 1)
ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW, _ASM_PTR __HYPERVISOR_VIRT_START)
ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET, _ASM_PTR 0)
#endif /*CONFIG_XEN */