![Mukesh Rathor](/assets/img/avatar_default.png)
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>
167 lines
4.8 KiB
ArmAsm
167 lines
4.8 KiB
ArmAsm
/* Xen-specific pieces of head.S, intended to be included in the right
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place in head.S */
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#ifdef CONFIG_XEN
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#include <linux/elfnote.h>
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#include <linux/init.h>
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#include <asm/boot.h>
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#include <asm/asm.h>
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#include <asm/page_types.h>
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#include <xen/interface/elfnote.h>
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#include <xen/interface/features.h>
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#include <asm/xen/interface.h>
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#ifdef CONFIG_XEN_PVH
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#define PVH_FEATURES_STR "|writable_descriptor_tables|auto_translated_physmap|supervisor_mode_kernel"
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/* Note the lack of 'hvm_callback_vector'. Older hypervisor will
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* balk at this being part of XEN_ELFNOTE_FEATURES, so we put it in
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* XEN_ELFNOTE_SUPPORTED_FEATURES which older hypervisors will ignore.
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*/
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#define PVH_FEATURES ((1 << XENFEAT_writable_page_tables) | \
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(1 << XENFEAT_auto_translated_physmap) | \
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(1 << XENFEAT_supervisor_mode_kernel) | \
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(1 << XENFEAT_hvm_callback_vector))
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/* The XENFEAT_writable_page_tables is not stricly neccessary as we set that
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* up regardless whether this CONFIG option is enabled or not, but it
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* clarifies what the right flags need to be.
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*/
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#else
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#define PVH_FEATURES_STR ""
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#define PVH_FEATURES (0)
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#endif
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__INIT
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ENTRY(startup_xen)
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cld
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#ifdef CONFIG_X86_32
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mov %esi,xen_start_info
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mov $init_thread_union+THREAD_SIZE,%esp
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#else
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mov %rsi,xen_start_info
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mov $init_thread_union+THREAD_SIZE,%rsp
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#endif
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jmp xen_start_kernel
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__FINIT
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#ifdef CONFIG_XEN_PVH
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/*
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* xen_pvh_early_cpu_init() - early PVH VCPU initialization
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* @cpu: this cpu number (%rdi)
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* @entry: true if this is a secondary vcpu coming up on this entry
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* point, false if this is the boot CPU being initialized for
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* the first time (%rsi)
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*
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* Note: This is called as a function on the boot CPU, and is the entry point
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* on the secondary CPU.
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*/
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ENTRY(xen_pvh_early_cpu_init)
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mov %rsi, %r11
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/* Gather features to see if NX implemented. */
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mov $0x80000001, %eax
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cpuid
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mov %edx, %esi
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mov $MSR_EFER, %ecx
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rdmsr
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bts $_EFER_SCE, %eax
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bt $20, %esi
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jnc 1f /* No NX, skip setting it */
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bts $_EFER_NX, %eax
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1: wrmsr
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#ifdef CONFIG_SMP
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cmp $0, %r11b
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jne cpu_bringup_and_idle
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#endif
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ret
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#endif /* CONFIG_XEN_PVH */
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.pushsection .text
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.balign PAGE_SIZE
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ENTRY(hypercall_page)
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#define NEXT_HYPERCALL(x) \
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ENTRY(xen_hypercall_##x) \
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.skip 32
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NEXT_HYPERCALL(set_trap_table)
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NEXT_HYPERCALL(mmu_update)
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NEXT_HYPERCALL(set_gdt)
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NEXT_HYPERCALL(stack_switch)
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NEXT_HYPERCALL(set_callbacks)
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NEXT_HYPERCALL(fpu_taskswitch)
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NEXT_HYPERCALL(sched_op_compat)
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NEXT_HYPERCALL(platform_op)
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NEXT_HYPERCALL(set_debugreg)
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NEXT_HYPERCALL(get_debugreg)
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NEXT_HYPERCALL(update_descriptor)
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NEXT_HYPERCALL(ni)
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NEXT_HYPERCALL(memory_op)
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NEXT_HYPERCALL(multicall)
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NEXT_HYPERCALL(update_va_mapping)
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NEXT_HYPERCALL(set_timer_op)
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NEXT_HYPERCALL(event_channel_op_compat)
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NEXT_HYPERCALL(xen_version)
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NEXT_HYPERCALL(console_io)
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NEXT_HYPERCALL(physdev_op_compat)
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NEXT_HYPERCALL(grant_table_op)
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NEXT_HYPERCALL(vm_assist)
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NEXT_HYPERCALL(update_va_mapping_otherdomain)
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NEXT_HYPERCALL(iret)
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NEXT_HYPERCALL(vcpu_op)
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NEXT_HYPERCALL(set_segment_base)
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NEXT_HYPERCALL(mmuext_op)
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NEXT_HYPERCALL(xsm_op)
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NEXT_HYPERCALL(nmi_op)
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NEXT_HYPERCALL(sched_op)
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NEXT_HYPERCALL(callback_op)
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NEXT_HYPERCALL(xenoprof_op)
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NEXT_HYPERCALL(event_channel_op)
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NEXT_HYPERCALL(physdev_op)
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NEXT_HYPERCALL(hvm_op)
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NEXT_HYPERCALL(sysctl)
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NEXT_HYPERCALL(domctl)
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NEXT_HYPERCALL(kexec_op)
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NEXT_HYPERCALL(tmem_op) /* 38 */
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ENTRY(xen_hypercall_rsvr)
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.skip 320
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NEXT_HYPERCALL(mca) /* 48 */
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NEXT_HYPERCALL(arch_1)
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NEXT_HYPERCALL(arch_2)
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NEXT_HYPERCALL(arch_3)
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NEXT_HYPERCALL(arch_4)
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NEXT_HYPERCALL(arch_5)
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NEXT_HYPERCALL(arch_6)
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.balign PAGE_SIZE
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.popsection
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ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS, .asciz "linux")
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ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION, .asciz "2.6")
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ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION, .asciz "xen-3.0")
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#ifdef CONFIG_X86_32
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ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE, _ASM_PTR __PAGE_OFFSET)
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#else
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ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE, _ASM_PTR __START_KERNEL_map)
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#endif
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ELFNOTE(Xen, XEN_ELFNOTE_ENTRY, _ASM_PTR startup_xen)
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ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)
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ELFNOTE(Xen, XEN_ELFNOTE_FEATURES, .ascii "!writable_page_tables|pae_pgdir_above_4gb"; .asciz PVH_FEATURES_STR)
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ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES, .long (PVH_FEATURES) |
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(1 << XENFEAT_writable_page_tables) |
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(1 << XENFEAT_dom0))
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ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE, .asciz "yes")
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ELFNOTE(Xen, XEN_ELFNOTE_LOADER, .asciz "generic")
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ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
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.quad _PAGE_PRESENT; .quad _PAGE_PRESENT)
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ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long 1)
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ELFNOTE(Xen, XEN_ELFNOTE_MOD_START_PFN, .long 1)
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ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW, _ASM_PTR __HYPERVISOR_VIRT_START)
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ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET, _ASM_PTR 0)
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#endif /*CONFIG_XEN */
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