From: David Gibson <david@gibson.dropbear.id.au>
To: Paul Mackerras <paulus@ozlabs.org>
Cc: linuxppc-dev@ozlabs.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH v3 21/33] KVM: PPC: Book3S HV: Framework to handle HV Emulation Assist Interrupt
Date: Wed, 3 Oct 2018 15:13:01 +1000 [thread overview]
Message-ID: <20181003051301.GO1886@umbus.fritz.box> (raw)
In-Reply-To: <1538479892-14835-22-git-send-email-paulus@ozlabs.org>
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On Tue, Oct 02, 2018 at 09:31:20PM +1000, Paul Mackerras wrote:
> From: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
>
> A HEAI (hypervisor emulation assistance interrupt) occurs when a
> hypervisor resource or instruction is used in a privileged but
> non-hypervisor state and the LPCR_EVIRT bit is set in LPCR. When
> this occurs bit 45 is set in HSRR1. Detect the occurrence of this,
> and if userspace has enabled the nested virtualization capability
> on the VM, then call the code to handle it accordingly.
>
> With LPCR[EVIRT] set, we also get HEAI (without bit 45 set) for
> mfspr or mtspr to unimplemented SPR numbers. For these accesses,
> we emulate the EVIRT=0 behaviour, which is to make the access
> a no-op for privileged software unless it is accessing SPR 0,
> 4, 5 or 6. Problem-state accesses and accesses to SPR 0, 4, 5
> or 6 generate an illegal-instruction type program interrupt.
>
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Do we still need this if we're moving to paravirt tlbie?
> ---
> arch/powerpc/include/asm/kvm_book3s.h | 2 +
> arch/powerpc/include/asm/reg.h | 1 +
> arch/powerpc/kvm/book3s_hv.c | 87 ++++++++++++++++++++++-------------
> arch/powerpc/kvm/book3s_hv_nested.c | 55 ++++++++++++++++++++++
> 4 files changed, 113 insertions(+), 32 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
> index 093fd70..0a97446 100644
> --- a/arch/powerpc/include/asm/kvm_book3s.h
> +++ b/arch/powerpc/include/asm/kvm_book3s.h
> @@ -287,6 +287,8 @@ void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr);
> void kvmhv_restore_hv_return_state(struct kvm_vcpu *vcpu,
> struct hv_guest_state *hr);
> long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu);
> +int kvmhv_emulate_priv(struct kvm_run *run, struct kvm_vcpu *vcpu,
> + unsigned int instr);
>
> void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac);
>
> diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
> index 6fda746..9c42abf 100644
> --- a/arch/powerpc/include/asm/reg.h
> +++ b/arch/powerpc/include/asm/reg.h
> @@ -456,6 +456,7 @@
> #define LPCR_HVICE ASM_CONST(0x0000000000000002) /* P9: HV interrupt enable */
> #define LPCR_HDICE ASM_CONST(0x0000000000000001) /* Hyp Decr enable (HV,PR,EE) */
> #define LPCR_UPRT ASM_CONST(0x0000000000400000) /* Use Process Table (ISA 3) */
> +#define LPCR_EVIRT ASM_CONST(0x0000000000200000) /* Enhanced Virtualisation */
> #define LPCR_HR ASM_CONST(0x0000000000100000)
> #ifndef SPRN_LPID
> #define SPRN_LPID 0x13F /* Logical Partition Identifier */
> diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
> index 134d7c7..b975683 100644
> --- a/arch/powerpc/kvm/book3s_hv.c
> +++ b/arch/powerpc/kvm/book3s_hv.c
> @@ -1027,30 +1027,6 @@ static int kvmppc_hcall_impl_hv(unsigned long cmd)
> return kvmppc_hcall_impl_hv_realmode(cmd);
> }
>
> -static int kvmppc_emulate_debug_inst(struct kvm_run *run,
> - struct kvm_vcpu *vcpu)
> -{
> - u32 last_inst;
> -
> - if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
> - EMULATE_DONE) {
> - /*
> - * Fetch failed, so return to guest and
> - * try executing it again.
> - */
> - return RESUME_GUEST;
> - }
> -
> - if (last_inst == KVMPPC_INST_SW_BREAKPOINT) {
> - run->exit_reason = KVM_EXIT_DEBUG;
> - run->debug.arch.address = kvmppc_get_pc(vcpu);
> - return RESUME_HOST;
> - } else {
> - kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
> - return RESUME_GUEST;
> - }
> -}
> -
> static void do_nothing(void *x)
> {
> }
> @@ -1144,6 +1120,23 @@ static int kvmppc_emulate_doorbell_instr(struct kvm_vcpu *vcpu)
> return RESUME_GUEST;
> }
>
> +static int kvmhv_emulate_unknown_spr(struct kvm_vcpu *vcpu, u32 instr)
> +{
> + u32 spr = get_sprn(instr);
> +
> + /*
> + * In privileged state, access to unimplemented SPRs is a no-op
> + * except for SPR 0, 4, 5 and 6. All other accesses get turned
> + * into illegal-instruction program interrupts.
> + */
> + if ((vcpu->arch.shregs.msr & MSR_PR) ||
> + spr == 0 || (4 <= spr && spr <= 6))
> + return EMULATE_FAIL;
> +
> + kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
> + return RESUME_GUEST;
> +}
> +
> static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu,
> struct task_struct *tsk)
> {
> @@ -1260,19 +1253,49 @@ static int kvmppc_handle_exit_hv(struct kvm_run *run, struct kvm_vcpu *vcpu,
> * to the guest. If guest debug is enabled, we need to check
> * whether the instruction is a software breakpoint instruction.
> * Accordingly return to Guest or Host.
> + * With LPCR[EVIRT] set, we also get these for accesses to
> + * unknown SPRs and for guests executing hypervisor privileged
> + * instructions.
> */
> case BOOK3S_INTERRUPT_H_EMUL_ASSIST:
> - if (vcpu->arch.emul_inst != KVM_INST_FETCH_FAILED)
> - vcpu->arch.last_inst = kvmppc_need_byteswap(vcpu) ?
> - swab32(vcpu->arch.emul_inst) :
> - vcpu->arch.emul_inst;
> - if (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP) {
> - r = kvmppc_emulate_debug_inst(run, vcpu);
> + {
> + u32 instr = vcpu->arch.emul_inst;
> + unsigned long srr1_bit = SRR1_PROGILL;
> +
> + vcpu->arch.last_inst = kvmppc_need_byteswap(vcpu) ?
> + swab32(instr) : instr;
> +
> + r = EMULATE_FAIL;
> + if (vcpu->arch.shregs.msr & SRR1_PROGPRIV) {
> + /*
> + * Tried to execute hypervisor privileged instruction
> + * or mtspr/mfspr on a hypervisor privileged SPR while
> + * MSR(HV | PR) == 0b00 -> Privileged but !HV state
> + */
> + srr1_bit = SRR1_PROGPRIV;
> + if (vcpu->kvm->arch.nested_enable)
> + r = kvmhv_emulate_priv(run, vcpu, instr);
> } else {
> - kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
> + /* Illegal instruction or unknown SPR access */
> + if (instr == KVMPPC_INST_SW_BREAKPOINT &&
> + (vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP)) {
> + run->exit_reason = KVM_EXIT_DEBUG;
> + run->debug.arch.address = kvmppc_get_pc(vcpu);
> + r = RESUME_HOST;
> + break;
> + }
> + if ((instr & 0xfc0006fe) == PPC_INST_MFSPR)
> + /* mfspr or mtspr to unknown SPR, may be noop */
> + r = kvmhv_emulate_unknown_spr(vcpu, instr);
> + }
> + if (r == EMULATE_FAIL) {
> + pr_debug("KVM: Couldn't emulate instruction 0x%.8x\n",
> + instr);
> + kvmppc_core_queue_program(vcpu, srr1_bit);
> r = RESUME_GUEST;
> }
> break;
> + }
> /*
> * This occurs if the guest (kernel or userspace), does something that
> * is prohibited by HFSCR.
> @@ -4612,7 +4635,7 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
> */
> if (cpu_has_feature(CPU_FTR_ARCH_300)) {
> lpcr &= ~LPCR_VPM0;
> - lpcr |= LPCR_HVICE | LPCR_HEIC;
> + lpcr |= LPCR_HVICE | LPCR_HEIC | LPCR_EVIRT;
>
> /*
> * If xive is enabled, we route 0x500 interrupts directly
> diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
> index 4a381b4..f8f9fab 100644
> --- a/arch/powerpc/kvm/book3s_hv_nested.c
> +++ b/arch/powerpc/kvm/book3s_hv_nested.c
> @@ -15,6 +15,7 @@
> #include <asm/mmu.h>
> #include <asm/pgtable.h>
> #include <asm/pgalloc.h>
> +#include <asm/disassemble.h>
>
> static struct patb_entry *pseries_partition_tb;
>
> @@ -515,3 +516,57 @@ long kvmhv_nested_page_fault(struct kvm_vcpu *vcpu)
> {
> return RESUME_HOST;
> }
> +
> +static int kvmhv_emulate_priv_mtspr(struct kvm_run *run, struct kvm_vcpu *vcpu,
> + unsigned int instr)
> +{
> + return EMULATE_FAIL;
> +}
> +
> +static int kvmhv_emulate_priv_mfspr(struct kvm_run *run, struct kvm_vcpu *vcpu,
> + unsigned int instr)
> +{
> + return EMULATE_FAIL;
> +}
> +
> +static int kvmhv_emulate_priv_op_31(struct kvm_run *run, struct kvm_vcpu *vcpu,
> + unsigned int instr)
> +{
> + return EMULATE_FAIL;
> +}
> +
> +static int kvmhv_emulate_priv_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
> + unsigned int instr)
> +{
> + return EMULATE_FAIL;
> +}
> +
> +int kvmhv_emulate_priv(struct kvm_run *run, struct kvm_vcpu *vcpu,
> + unsigned int instr)
> +{
> + int rc = EMULATE_FAIL;
> +
> + switch (get_op(instr)) {
> + case 31:
> + switch (get_xop(instr)) {
> + case OP_31_XOP_MTSPR:
> + rc = kvmhv_emulate_priv_mtspr(run, vcpu, instr);
> + break;
> + case OP_31_XOP_MFSPR:
> + rc = kvmhv_emulate_priv_mfspr(run, vcpu, instr);
> + break;
> + default:
> + rc = kvmhv_emulate_priv_op_31(run, vcpu, instr);
> + break;
> + }
> +
> + if (rc == EMULATE_DONE)
> + kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);
> + break;
> + default:
> + rc = kvmhv_emulate_priv_op(run, vcpu, instr);
> + break;
> + }
> +
> + return rc;
> +}
--
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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next prev parent reply other threads:[~2018-10-03 5:13 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-02 11:30 [PATCH v3 00/33] KVM: PPC: Book3S HV: Nested HV virtualization Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 01/33] powerpc: Turn off CPU_FTR_P9_TM_HV_ASSIST in non-hypervisor mode Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 02/33] KVM: PPC: Book3S: Simplify external interrupt handling Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 03/33] KVM: PPC: Book3S HV: Remove left-over code in XICS-on-XIVE emulation Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 04/33] KVM: PPC: Book3S HV: Move interrupt delivery on guest entry to C code Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 05/33] KVM: PPC: Book3S HV: Extract PMU save/restore operations as C-callable functions Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 06/33] KVM: PPC: Book3S HV: Simplify real-mode interrupt handling Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 07/33] KVM: PPC: Book3S: Rework TM save/restore code and make it C-callable Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 08/33] KVM: PPC: Book3S HV: Call kvmppc_handle_exit_hv() with vcore unlocked Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 09/33] KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 10/33] KVM: PPC: Book3S HV: Handle hypervisor instruction faults better Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 11/33] KVM: PPC: Book3S HV: Add a debugfs file to dump radix mappings Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 12/33] KVM: PPC: Use ccr field in pt_regs struct embedded in vcpu struct Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 13/33] KVM: PPC: Book3S HV: Clear partition table entry on vm teardown Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 14/33] KVM: PPC: Book3S HV: Make kvmppc_mmu_radix_xlate process/partition table agnostic Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 15/33] KVM: PPC: Book3S HV: Refactor radix page fault handler Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 16/33] KVM: PPC: Book3S HV: Use kvmppc_unmap_pte() in kvm_unmap_radix() Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 17/33] KVM: PPC: Book3S HV: Framework and hcall stubs for nested virtualization Paul Mackerras
2018-10-03 3:17 ` David Gibson
2018-10-02 11:31 ` [PATCH v3 18/33] KVM: PPC: Book3S HV: Nested guest entry via hypercall Paul Mackerras
2018-10-03 5:12 ` David Gibson
2018-10-02 11:31 ` [PATCH v3 19/33] KVM: PPC: Book3S HV: Use XICS hypercalls when running as a nested hypervisor Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 20/33] KVM: PPC: Book3S HV: Handle hypercalls correctly when nested Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 21/33] KVM: PPC: Book3S HV: Framework to handle HV Emulation Assist Interrupt Paul Mackerras
2018-10-03 5:13 ` David Gibson [this message]
2018-10-02 11:31 ` [PATCH v3 22/33] KVM: PPC: Book3S HV: Handle page fault for a nested guest Paul Mackerras
2018-10-03 5:39 ` David Gibson
2018-10-03 5:42 ` David Gibson
2018-10-04 9:21 ` Paul Mackerras
2018-10-05 2:46 ` David Gibson
2018-10-02 11:31 ` [PATCH v3 23/33] KVM: PPC: Book3S HV: Introduce rmap to track nested guest mappings Paul Mackerras
2018-10-03 5:56 ` David Gibson
2018-10-04 3:05 ` Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 24/33] KVM: PPC: Book3S HV: Emulate Privileged TLBIE for guest hypervisors Paul Mackerras
2018-10-03 5:56 ` David Gibson
2018-10-02 11:31 ` [PATCH v3 25/33] KVM: PPC: Book3S HV: Invalidate TLB when nested vcpu moves physical cpu Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 26/33] KVM: PPC: Book3S HV: Don't access HFSCR, LPIDR or LPCR when running nested Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 27/33] KVM: PPC: Book3S HV: Add one-reg interface to virtual PTCR register Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 28/33] KVM: PPC: Book3S HV: Sanitise hv_regs on nested guest entry Paul Mackerras
2018-10-03 6:07 ` David Gibson
2018-10-02 11:31 ` [PATCH v3 29/33] KVM: PPC: Book3S HV: Handle differing endianness for H_ENTER_NESTED Paul Mackerras
2018-10-03 6:13 ` David Gibson
2018-10-04 9:29 ` Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 30/33] KVM: PPC: Book3S HV: Allow HV module to load without hypervisor mode Paul Mackerras
2018-10-03 6:15 ` David Gibson
2018-10-04 3:03 ` Paul Mackerras
2018-10-05 3:05 ` David Gibson
2018-10-02 11:31 ` [PATCH v3 31/33] KVM: PPC: Book3S HV: Add nested shadow page tables to debugfs Paul Mackerras
2018-10-02 11:31 ` [PATCH v3 32/33] KVM: PPC: Book3S HV: Use hypercalls for TLB invalidation when nested Paul Mackerras
2018-10-03 6:17 ` David Gibson
2018-10-02 11:31 ` [PATCH v3 33/33] KVM: PPC: Book3S HV: Add a VM capability to enable nested virtualization Paul Mackerras
2018-10-03 6:21 ` David Gibson
2018-10-04 9:48 ` Paul Mackerras
2018-10-05 3:29 ` David Gibson
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