[PATCH V2 2/2] powerpc/kvm: Update kvmppc_set_arch_compat() for ISA v3.00

[Suraj Jitindar Singh]

The function kvmppc_set_arch_compat() is used to determine the value of the
processor compatibility register (PCR) for a guest running in a given
compatibility mode. There is currently no support for v3.00 of the ISA.

Add support for v3.00 of the ISA which adds an ISA v2.07 compatilibity mode
to the PCR.

We also add a check to ensure the processor we are running on is capable of
emulating the chosen processor (for example a POWER7 cannot emulate a
POWER8, similarly with a POWER8 and a POWER9).

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh at gmail.com>
---
 arch/powerpc/kvm/book3s_hv.c | 32 +++++++++++++++++++++++---------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 3686471..24681e7 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -311,24 +311,38 @@ static int kvmppc_set_arch_compat(struct kvm_vcpu *vcpu, u32 arch_compat)
 			 * If an arch bit is set in PCR, all the defined
 			 * higher-order arch bits also have to be set.
 			 */
-			pcr = PCR_ARCH_206 | PCR_ARCH_205;
+			if (cpu_has_feature(CPU_FTR_ARCH_206))
+				pcr |= PCR_ARCH_205;
+			if (cpu_has_feature(CPU_FTR_ARCH_207S))
+				pcr |= PCR_ARCH_206;
+			if (cpu_has_feature(CPU_FTR_ARCH_300))
+				pcr |= PCR_ARCH_207;
 			break;
 		case PVR_ARCH_206:
 		case PVR_ARCH_206p:
-			pcr = PCR_ARCH_206;
+			/* Must be at least v2.06 to (emulate) it */
+			if (!cpu_has_feature(CPU_FTR_ARCH_206))
+				return -EINVAL;
+			if (cpu_has_feature(CPU_FTR_ARCH_207S))
+				pcr |= PCR_ARCH_206;
+			if (cpu_has_feature(CPU_FTR_ARCH_300))
+				pcr |= PCR_ARCH_207;
 			break;
 		case PVR_ARCH_207:
+			/* Must be at least v2.07 to (emulate) it */
+			if (!cpu_has_feature(CPU_FTR_ARCH_207S))
+				return -EINVAL;
+			if (cpu_has_feature(CPU_FTR_ARCH_300))
+				pcr |= PCR_ARCH_207;
+			break;
+		case PVR_ARCH_300:
+			/* Must be at least v3.00 to (emulate) it */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300))
+				return -EINVAL;
 			break;
 		default:
 			return -EINVAL;
 		}
-
-		if (!cpu_has_feature(CPU_FTR_ARCH_207S)) {
-			/* POWER7 can't emulate POWER8 */
-			if (!(pcr & PCR_ARCH_206))
-				return -EINVAL;
-			pcr &= ~PCR_ARCH_206;
-		}
 	}
 
 	spin_lock(&vc->lock);
-- 
2.5.5