KVM: PPC: Book3S HV: Handle hypercalls correctly when nested

When we are running as a nested hypervisor, we use a hypercall to
enter the guest rather than code in book3s_hv_rmhandlers.S.  This means
that the hypercall handlers listed in hcall_real_table never get called.
There are some hypercalls that are handled there and not in
kvmppc_pseries_do_hcall(), which therefore won't get processed for
a nested guest.

To fix this, we add cases to kvmppc_pseries_do_hcall() to handle those
hypercalls, with the following exceptions:

- The HPT hypercalls (H_ENTER, H_REMOVE, etc.) are not handled because
  we only support radix mode for nested guests.

- H_CEDE has to be handled specially because the cede logic in
  kvmhv_run_single_vcpu assumes that it has been processed by the time
  that kvmhv_p9_guest_entry() returns.  Therefore we put a special
  case for H_CEDE in kvmhv_p9_guest_entry().

For the XICS hypercalls, if real-mode processing is enabled, then the
virtual-mode handlers assume that they are being called only to finish
up the operation.  Therefore we turn off the real-mode flag in the XICS
code when running as a nested hypervisor.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 5c9b00c..c55ba3b 100644 (file)
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -167,4 +167,8 @@ void kvmhv_load_guest_pmu(struct kvm_vcpu *vcpu);
 
 int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu);
 
+long kvmppc_h_set_dabr(struct kvm_vcpu *vcpu, unsigned long dabr);
+long kvmppc_h_set_xdabr(struct kvm_vcpu *vcpu, unsigned long dabr,
+                       unsigned long dabrx);
+
 #endif /* _ASM_POWERPC_ASM_PROTOTYPES_H */

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index e8e56c1..a879125 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -50,6 +50,7 @@
 #include <asm/reg.h>
 #include <asm/ppc-opcode.h>
 #include <asm/asm-prototypes.h>
+#include <asm/archrandom.h>
 #include <asm/debug.h>
 #include <asm/disassemble.h>
 #include <asm/cputable.h>
@@ -915,6 +916,19 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
                        break;
                }
                return RESUME_HOST;
+       case H_SET_DABR:
+               ret = kvmppc_h_set_dabr(vcpu, kvmppc_get_gpr(vcpu, 4));
+               break;
+       case H_SET_XDABR:
+               ret = kvmppc_h_set_xdabr(vcpu, kvmppc_get_gpr(vcpu, 4),
+                                               kvmppc_get_gpr(vcpu, 5));
+               break;
+       case H_GET_TCE:
+               ret = kvmppc_h_get_tce(vcpu, kvmppc_get_gpr(vcpu, 4),
+                                               kvmppc_get_gpr(vcpu, 5));
+               if (ret == H_TOO_HARD)
+                       return RESUME_HOST;
+               break;
        case H_PUT_TCE:
                ret = kvmppc_h_put_tce(vcpu, kvmppc_get_gpr(vcpu, 4),
                                                kvmppc_get_gpr(vcpu, 5),
@@ -938,6 +952,10 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
                if (ret == H_TOO_HARD)
                        return RESUME_HOST;
                break;
+       case H_RANDOM:
+               if (!powernv_get_random_long(&vcpu->arch.regs.gpr[4]))
+                       ret = H_HARDWARE;
+               break;
 
        case H_SET_PARTITION_TABLE:
                ret = H_FUNCTION;
@@ -966,6 +984,24 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
        return RESUME_GUEST;
 }
 
+/*
+ * Handle H_CEDE in the nested virtualization case where we haven't
+ * called the real-mode hcall handlers in book3s_hv_rmhandlers.S.
+ * This has to be done early, not in kvmppc_pseries_do_hcall(), so
+ * that the cede logic in kvmppc_run_single_vcpu() works properly.
+ */
+static void kvmppc_nested_cede(struct kvm_vcpu *vcpu)
+{
+       vcpu->arch.shregs.msr |= MSR_EE;
+       vcpu->arch.ceded = 1;
+       smp_mb();
+       if (vcpu->arch.prodded) {
+               vcpu->arch.prodded = 0;
+               smp_mb();
+               vcpu->arch.ceded = 0;
+       }
+}
+
 static int kvmppc_hcall_impl_hv(unsigned long cmd)
 {
        switch (cmd) {
@@ -3424,6 +3460,13 @@ int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
                vcpu->arch.shregs.msr = vcpu->arch.regs.msr;
                vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
                vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
+
+               /* H_CEDE has to be handled now, not later */
+               if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
+                   kvmppc_get_gpr(vcpu, 3) == H_CEDE) {
+                       kvmppc_nested_cede(vcpu);
+                       trap = 0;
+               }
        } else {
                trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
        }

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index a945369..9b8d50a 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -2466,6 +2466,7 @@ hcall_real_table:
 hcall_real_table_end:
 
 _GLOBAL(kvmppc_h_set_xdabr)
+EXPORT_SYMBOL_GPL(kvmppc_h_set_xdabr)
        andi.   r0, r5, DABRX_USER | DABRX_KERNEL
        beq     6f
        li      r0, DABRX_USER | DABRX_KERNEL | DABRX_BTI
@@ -2475,6 +2476,7 @@ _GLOBAL(kvmppc_h_set_xdabr)
        blr
 
 _GLOBAL(kvmppc_h_set_dabr)
+EXPORT_SYMBOL_GPL(kvmppc_h_set_dabr)
        li      r5, DABRX_USER | DABRX_KERNEL
 3:
 BEGIN_FTR_SECTION

diff --git a/arch/powerpc/kvm/book3s_xics.c b/arch/powerpc/kvm/book3s_xics.c
index d9ba1b0..b0b2bfc 100644 (file)
--- a/arch/powerpc/kvm/book3s_xics.c
+++ b/arch/powerpc/kvm/book3s_xics.c
@@ -1390,7 +1390,8 @@ static int kvmppc_xics_create(struct kvm_device *dev, u32 type)
        }
 
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-       if (cpu_has_feature(CPU_FTR_ARCH_206)) {
+       if (cpu_has_feature(CPU_FTR_ARCH_206) &&
+           cpu_has_feature(CPU_FTR_HVMODE)) {
                /* Enable real mode support */
                xics->real_mode = ENABLE_REALMODE;
                xics->real_mode_dbg = DEBUG_REALMODE;