KVM: PPC: Handle some PAPR hcalls in the kernel

This adds the infrastructure for handling PAPR hcalls in the kernel,
either early in the guest exit path while we are still in real mode,
or later once the MMU has been turned back on and we are in the full
kernel context.  The advantage of handling hcalls in real mode if
possible is that we avoid two partition switches -- and this will
become more important when we support SMT4 guests, since a partition
switch means we have to pull all of the threads in the core out of
the guest.  The disadvantage is that we can only access the kernel
linear mapping, not anything vmalloced or ioremapped, since the MMU
is off.

This also adds code to handle the following hcalls in real mode:

H_ENTER       Add an HPTE to the hashed page table
H_REMOVE      Remove an HPTE from the hashed page table
H_READ        Read HPTEs from the hashed page table
H_PROTECT     Change the protection bits in an HPTE
H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table
H_SET_DABR    Set the data address breakpoint register

Plus code to handle the following hcalls in the kernel:

H_CEDE        Idle the vcpu until an interrupt or H_PROD hcall arrives
H_PROD        Wake up a ceded vcpu
H_REGISTER_VPA Register a virtual processor area (VPA)

The code that runs in real mode has to be in the base kernel, not in
the module, if KVM is compiled as a module.  The real-mode code can
only access the kernel linear mapping, not vmalloc or ioremap space.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 4a3f790d5fc..6ebf1721680 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -59,6 +59,10 @@ struct kvm;
 struct kvm_run;
 struct kvm_vcpu;
 
+struct lppaca;
+struct slb_shadow;
+struct dtl;
+
 struct kvm_vm_stat {
 	u32 remote_tlb_flush;
 };
@@ -344,7 +348,14 @@ struct kvm_vcpu_arch {
 	u64 dec_expires;
 	unsigned long pending_exceptions;
 	u16 last_cpu;
+	u8 ceded;
+	u8 prodded;
 	u32 last_inst;
+
+	struct lppaca *vpa;
+	struct slb_shadow *slb_shadow;
+	struct dtl *dtl;
+	struct dtl *dtl_end;
 	int trap;
 	struct kvm_vcpu_arch_shared *shared;
 	unsigned long magic_page_pa; /* phys addr to map the magic page to */