linux/arch/powerpc/include/asm/kvm_booke_hv_asm.h
Scott Wood d30f6e4800 KVM: PPC: booke: category E.HV (GS-mode) support
Chips such as e500mc that implement category E.HV in Power ISA 2.06
provide hardware virtualization features, including a new MSR mode for
guest state.  The guest OS can perform many operations without trapping
into the hypervisor, including transitions to and from guest userspace.

Since we can use SRR1[GS] to reliably tell whether an exception came from
guest state, instead of messing around with IVPR, we use DO_KVM similarly
to book3s.

Current issues include:
 - Machine checks from guest state are not routed to the host handler.
 - The guest can cause a host oops by executing an emulated instruction
   in a page that lacks read permission.  Existing e500/4xx support has
   the same problem.

Includes work by Ashish Kalra <Ashish.Kalra@freescale.com>,
Varun Sethi <Varun.Sethi@freescale.com>, and
Liu Yu <yu.liu@freescale.com>.

Signed-off-by: Scott Wood <scottwood@freescale.com>
[agraf: remove pt_regs usage]
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08 12:51:19 +03:00

50 lines
1.5 KiB
C

/*
* Copyright 2010-2011 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*/
#ifndef ASM_KVM_BOOKE_HV_ASM_H
#define ASM_KVM_BOOKE_HV_ASM_H
#ifdef __ASSEMBLY__
/*
* All exceptions from guest state must go through KVM
* (except for those which are delivered directly to the guest) --
* there are no exceptions for which we fall through directly to
* the normal host handler.
*
* Expected inputs (normal exceptions):
* SCRATCH0 = saved r10
* r10 = thread struct
* r11 = appropriate SRR1 variant (currently used as scratch)
* r13 = saved CR
* *(r10 + THREAD_NORMSAVE(0)) = saved r11
* *(r10 + THREAD_NORMSAVE(2)) = saved r13
*
* Expected inputs (crit/mcheck/debug exceptions):
* appropriate SCRATCH = saved r8
* r8 = exception level stack frame
* r9 = *(r8 + _CCR) = saved CR
* r11 = appropriate SRR1 variant (currently used as scratch)
* *(r8 + GPR9) = saved r9
* *(r8 + GPR10) = saved r10 (r10 not yet clobbered)
* *(r8 + GPR11) = saved r11
*/
.macro DO_KVM intno srr1
#ifdef CONFIG_KVM_BOOKE_HV
BEGIN_FTR_SECTION
mtocrf 0x80, r11 /* check MSR[GS] without clobbering reg */
bf 3, kvmppc_resume_\intno\()_\srr1
b kvmppc_handler_\intno\()_\srr1
kvmppc_resume_\intno\()_\srr1:
END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
#endif
.endm
#endif /*__ASSEMBLY__ */
#endif /* ASM_KVM_BOOKE_HV_ASM_H */