[PATCH v2 21/33] KVM: PPC: Book3S HV: Handle hypercalls correctly when nested
Paul Mackerras
paulus at ozlabs.org
Fri Sep 28 19:45:51 AEST 2018
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 at gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus at ozlabs.org>
---
arch/powerpc/include/asm/asm-prototypes.h | 4 +++
arch/powerpc/kvm/book3s_hv.c | 43 +++++++++++++++++++++++++++++++
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 2 ++
arch/powerpc/kvm/book3s_xics.c | 3 ++-
4 files changed, 51 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 5c9b00c..c55ba3b 100644
--- 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 8d2f91f..84d08d5 100644
--- 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) {
@@ -3422,6 +3458,13 @@ 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 8da73ea..d8b26be 100644
--- 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
--- 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;
--
2.7.4
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