KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation.
Some PowerNV systems include a hardware random-number generator.
This HWRNG is present on POWER7+ and POWER8 chips and is capable of
generating one 64-bit random number every microsecond. The random
numbers are produced by sampling a set of 64 unstable high-frequency
oscillators and are almost completely entropic.
PAPR defines an H_RANDOM hypercall which guests can use to obtain one
64-bit random sample from the HWRNG. This adds a real-mode
implementation of the H_RANDOM hypercall. This hypercall was
implemented in real mode because the latency of reading the HWRNG is
generally small compared to the latency of a guest exit and entry for
all the threads in the same virtual core.
Userspace can detect the presence of the HWRNG and the H_RANDOM
implementation by querying the KVM_CAP_PPC_HWRNG capability. The
H_RANDOM hypercall implementation will only be invoked when the guest
does an H_RANDOM hypercall if userspace first enables the in-kernel
H_RANDOM implementation using the KVM_CAP_PPC_ENABLE_HCALL capability.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 6cbf163..0814ca1 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1839,6 +1839,121 @@
.long 0 /* 0x12c */
.long 0 /* 0x130 */
.long DOTSYM(kvmppc_h_set_xdabr) - hcall_real_table
+ .long 0 /* 0x138 */
+ .long 0 /* 0x13c */
+ .long 0 /* 0x140 */
+ .long 0 /* 0x144 */
+ .long 0 /* 0x148 */
+ .long 0 /* 0x14c */
+ .long 0 /* 0x150 */
+ .long 0 /* 0x154 */
+ .long 0 /* 0x158 */
+ .long 0 /* 0x15c */
+ .long 0 /* 0x160 */
+ .long 0 /* 0x164 */
+ .long 0 /* 0x168 */
+ .long 0 /* 0x16c */
+ .long 0 /* 0x170 */
+ .long 0 /* 0x174 */
+ .long 0 /* 0x178 */
+ .long 0 /* 0x17c */
+ .long 0 /* 0x180 */
+ .long 0 /* 0x184 */
+ .long 0 /* 0x188 */
+ .long 0 /* 0x18c */
+ .long 0 /* 0x190 */
+ .long 0 /* 0x194 */
+ .long 0 /* 0x198 */
+ .long 0 /* 0x19c */
+ .long 0 /* 0x1a0 */
+ .long 0 /* 0x1a4 */
+ .long 0 /* 0x1a8 */
+ .long 0 /* 0x1ac */
+ .long 0 /* 0x1b0 */
+ .long 0 /* 0x1b4 */
+ .long 0 /* 0x1b8 */
+ .long 0 /* 0x1bc */
+ .long 0 /* 0x1c0 */
+ .long 0 /* 0x1c4 */
+ .long 0 /* 0x1c8 */
+ .long 0 /* 0x1cc */
+ .long 0 /* 0x1d0 */
+ .long 0 /* 0x1d4 */
+ .long 0 /* 0x1d8 */
+ .long 0 /* 0x1dc */
+ .long 0 /* 0x1e0 */
+ .long 0 /* 0x1e4 */
+ .long 0 /* 0x1e8 */
+ .long 0 /* 0x1ec */
+ .long 0 /* 0x1f0 */
+ .long 0 /* 0x1f4 */
+ .long 0 /* 0x1f8 */
+ .long 0 /* 0x1fc */
+ .long 0 /* 0x200 */
+ .long 0 /* 0x204 */
+ .long 0 /* 0x208 */
+ .long 0 /* 0x20c */
+ .long 0 /* 0x210 */
+ .long 0 /* 0x214 */
+ .long 0 /* 0x218 */
+ .long 0 /* 0x21c */
+ .long 0 /* 0x220 */
+ .long 0 /* 0x224 */
+ .long 0 /* 0x228 */
+ .long 0 /* 0x22c */
+ .long 0 /* 0x230 */
+ .long 0 /* 0x234 */
+ .long 0 /* 0x238 */
+ .long 0 /* 0x23c */
+ .long 0 /* 0x240 */
+ .long 0 /* 0x244 */
+ .long 0 /* 0x248 */
+ .long 0 /* 0x24c */
+ .long 0 /* 0x250 */
+ .long 0 /* 0x254 */
+ .long 0 /* 0x258 */
+ .long 0 /* 0x25c */
+ .long 0 /* 0x260 */
+ .long 0 /* 0x264 */
+ .long 0 /* 0x268 */
+ .long 0 /* 0x26c */
+ .long 0 /* 0x270 */
+ .long 0 /* 0x274 */
+ .long 0 /* 0x278 */
+ .long 0 /* 0x27c */
+ .long 0 /* 0x280 */
+ .long 0 /* 0x284 */
+ .long 0 /* 0x288 */
+ .long 0 /* 0x28c */
+ .long 0 /* 0x290 */
+ .long 0 /* 0x294 */
+ .long 0 /* 0x298 */
+ .long 0 /* 0x29c */
+ .long 0 /* 0x2a0 */
+ .long 0 /* 0x2a4 */
+ .long 0 /* 0x2a8 */
+ .long 0 /* 0x2ac */
+ .long 0 /* 0x2b0 */
+ .long 0 /* 0x2b4 */
+ .long 0 /* 0x2b8 */
+ .long 0 /* 0x2bc */
+ .long 0 /* 0x2c0 */
+ .long 0 /* 0x2c4 */
+ .long 0 /* 0x2c8 */
+ .long 0 /* 0x2cc */
+ .long 0 /* 0x2d0 */
+ .long 0 /* 0x2d4 */
+ .long 0 /* 0x2d8 */
+ .long 0 /* 0x2dc */
+ .long 0 /* 0x2e0 */
+ .long 0 /* 0x2e4 */
+ .long 0 /* 0x2e8 */
+ .long 0 /* 0x2ec */
+ .long 0 /* 0x2f0 */
+ .long 0 /* 0x2f4 */
+ .long 0 /* 0x2f8 */
+ .long 0 /* 0x2fc */
+ .long DOTSYM(kvmppc_h_random) - hcall_real_table
.globl hcall_real_table_end
hcall_real_table_end: