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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>
hifive-unleashed-5.1
Paul Mackerras 2018-10-08 16:31:06 +11:00 committed by Michael Ellerman
parent f3c18e9342
commit 4bad77799f
4 changed files with 51 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/powerpc/include/asm/asm-prototypes.h
View File

@ -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 */

43
arch/powerpc/kvm/book3s_hv.c
View File

@ -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);
}

2
arch/powerpc/kvm/book3s_hv_rmhandlers.S
View File

@ -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

3
arch/powerpc/kvm/book3s_xics.c
View File

@ -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;