On Fri, Sep 21, 2018 at 08:01:53PM +1000, Paul Mackerras wrote:
> 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.
>
> Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx>
Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
> ---
> 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 9052a34..61de6ac 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;
> @@ -963,6 +981,24 @@ 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) {
> @@ -3420,6 +3456,13 @@ 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 &&
> + kvmppc_get_gpr(vcpu, 3) == H_CEDE) {
> + kvmppc_nested_cede(vcpu);
> + trap = 0;
> + }
> } else {
> trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit);
> }
> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> index 04fcaa4..a4780be 100644
> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> @@ -2462,6 +2462,7 @@ 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
> @@ -2471,6 +2472,7 @@ _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;
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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