[PATCH v5 20/33] KVM: PPC: Book3S HV: Handle hypercalls correctly when nested
From: Paul Mackerras <hidden>
Date: 2018-10-08 06:23:52
Also in:
kvm
Subsystem:
kernel virtual machine for powerpc (kvm/powerpc), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
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 <redacted> Signed-off-by: Paul Mackerras <redacted> --- 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 dd84252..dc25461 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 a945369..9b8d50a 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;
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2.7.4