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, 5 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index fd8201dddd4b..1c324ff55ea8 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -29,6 +29,10 @@
 #define H_LONG_BUSY_ORDER_100_SEC       9905  /* Long busy, hint that 100sec \
                                                  is a good time to retry */
 #define H_LONG_BUSY_END_RANGE           9905  /* End of long busy range */
+
+/* Internal value used in book3s_hv kvm support; not returned to guests */
+#define H_TOO_HARD      9999
+
 #define H_HARDWARE      -1      /* Hardware error */
 #define H_FUNCTION      -2      /* Function not supported */
 #define H_PRIVILEGE     -3      /* Caller not privileged */
@@ -100,6 +104,7 @@
 #define H_PAGE_SET_ACTIVE       H_PAGE_STATE_CHANGE
 #define H_AVPN                  (1UL<<(63-32))  /* An avpn is provided as a sanity test */
 #define H_ANDCOND               (1UL<<(63-33))
+#define H_LOCAL                 (1UL<<(63-35))
 #define H_ICACHE_INVALIDATE     (1UL<<(63-40))  /* icbi, etc.  (ignored for IO pages) */
 #define H_ICACHE_SYNCHRONIZE    (1UL<<(63-41))  /* dcbst, icbi, etc (ignored for IO pages */
 #define H_COALESCE_CAND (1UL<<(63-42))  /* page is a good candidate for coalescing */