From: Julien Thierry <julien.thierry@arm.com> To: Marc Zyngier <marc.zyngier@arm.com>, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Andre Przywara <andre.przywara@arm.com>, Dave Martin <Dave.Martin@arm.com> Subject: Re: [PATCH 16/59] KVM: arm64: nv: Save/Restore vEL2 sysregs Date: Tue, 25 Jun 2019 09:48:50 +0100 [thread overview] Message-ID: <800f3e9a-5b67-951b-34c2-60367c0697f9@arm.com> (raw) In-Reply-To: <20190621093843.220980-17-marc.zyngier@arm.com> On 06/21/2019 10:38 AM, Marc Zyngier wrote: > From: Andre Przywara <andre.przywara@arm.com> > > Whenever we need to restore the guest's system registers to the CPU, we > now need to take care of the EL2 system registers as well. Most of them > are accessed via traps only, but some have an immediate effect and also > a guest running in VHE mode would expect them to be accessible via their > EL1 encoding, which we do not trap. > > Split the current __sysreg_{save,restore}_el1_state() functions into > handling common sysregs, then differentiate between the guest running in > vEL2 and vEL1. > > For vEL2 we write the virtual EL2 registers with an identical format directly > into their EL1 counterpart, and translate the few registers that have a > different format for the same effect on the execution when running a > non-VHE guest guest hypervisor. > > [ Commit message reworked and many bug fixes applied by Marc Zyngier > and Christoffer Dall. ] > > Signed-off-by: Andre Przywara <andre.przywara@arm.com> > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> > --- > arch/arm64/kvm/hyp/sysreg-sr.c | 160 +++++++++++++++++++++++++++++++-- > 1 file changed, 153 insertions(+), 7 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c > index 62866a68e852..2abb9c3ff24f 100644 > --- a/arch/arm64/kvm/hyp/sysreg-sr.c > +++ b/arch/arm64/kvm/hyp/sysreg-sr.c [...] > @@ -124,10 +167,91 @@ static void __hyp_text __sysreg_restore_user_state(struct kvm_cpu_context *ctxt) > write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0); > } > > -static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt) > +static void __sysreg_restore_vel2_state(struct kvm_cpu_context *ctxt) > { > + u64 val; > + > + write_sysreg(read_cpuid_id(), vpidr_el2); > write_sysreg(ctxt->sys_regs[MPIDR_EL1], vmpidr_el2); > - write_sysreg(ctxt->sys_regs[CSSELR_EL1], csselr_el1); > + write_sysreg_el1(ctxt->sys_regs[MAIR_EL2], SYS_MAIR); > + write_sysreg_el1(ctxt->sys_regs[VBAR_EL2], SYS_VBAR); > + write_sysreg_el1(ctxt->sys_regs[CONTEXTIDR_EL2],SYS_CONTEXTIDR); > + write_sysreg_el1(ctxt->sys_regs[AMAIR_EL2], SYS_AMAIR); > + > + if (__vcpu_el2_e2h_is_set(ctxt)) { > + /* > + * In VHE mode those registers are compatible between > + * EL1 and EL2. > + */ > + write_sysreg_el1(ctxt->sys_regs[SCTLR_EL2], SYS_SCTLR); > + write_sysreg_el1(ctxt->sys_regs[CPTR_EL2], SYS_CPACR); > + write_sysreg_el1(ctxt->sys_regs[TTBR0_EL2], SYS_TTBR0); > + write_sysreg_el1(ctxt->sys_regs[TTBR1_EL2], SYS_TTBR1); > + write_sysreg_el1(ctxt->sys_regs[TCR_EL2], SYS_TCR); > + write_sysreg_el1(ctxt->sys_regs[CNTHCTL_EL2], SYS_CNTKCTL); > + } else { > + write_sysreg_el1(translate_sctlr(ctxt->sys_regs[SCTLR_EL2]), > + SYS_SCTLR); > + write_sysreg_el1(translate_cptr(ctxt->sys_regs[CPTR_EL2]), > + SYS_CPACR); > + write_sysreg_el1(translate_ttbr0(ctxt->sys_regs[TTBR0_EL2]), > + SYS_TTBR0); > + write_sysreg_el1(translate_tcr(ctxt->sys_regs[TCR_EL2]), > + SYS_TCR); > + write_sysreg_el1(translate_cnthctl(ctxt->sys_regs[CNTHCTL_EL2]), > + SYS_CNTKCTL); > + } > + > + /* > + * These registers can be modified behind our back by a fault > + * taken inside vEL2. Save them, always. > + */ > + write_sysreg_el1(ctxt->sys_regs[ESR_EL2], SYS_ESR); > + write_sysreg_el1(ctxt->sys_regs[AFSR0_EL2], SYS_AFSR0); > + write_sysreg_el1(ctxt->sys_regs[AFSR1_EL2], SYS_AFSR1); > + write_sysreg_el1(ctxt->sys_regs[FAR_EL2], SYS_FAR); > + write_sysreg(ctxt->sys_regs[SP_EL2], sp_el1); > + write_sysreg_el1(ctxt->sys_regs[ELR_EL2], SYS_ELR); > + > + val = __fixup_spsr_el2_write(ctxt, ctxt->sys_regs[SPSR_EL2]); > + write_sysreg_el1(val, SYS_SPSR); > +} > + > +static void __hyp_text __sysreg_restore_vel1_state(struct kvm_cpu_context *ctxt) > +{ > + u64 mpidr; > + > + if (has_vhe()) { > + struct kvm_vcpu *vcpu; > + > + /* > + * Warning: this hack only works on VHE, because we only > + * call this with the *guest* context, which is part of > + * struct kvm_vcpu. On a host context, you'd get pure junk. > + */ > + vcpu = container_of(ctxt, struct kvm_vcpu, arch.ctxt); This seems very fragile, just to find out whether the guest has hyp capabilities. It would be at least nice to make sure this is indeed a guest context. The *clean* way to do it could be to have a pointer to kvm_vcpu in the kvm_cpu_context which would be NULL for host contexts. Otherwise, I'm under the impression that for a host context, ctxt->sys_reg[HCR_EL2] == 0 and that this would also be true for a guest without nested virt capability. Could we use something like that here? Cheers, Julien _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
next prev parent reply other threads:[~2019-06-25 8:49 UTC|newest] Thread overview: 179+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-06-21 9:37 [PATCH 00/59] KVM: arm64: ARMv8.3 Nested Virtualization support Marc Zyngier 2019-06-21 9:37 ` [PATCH 01/59] KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s Marc Zyngier 2019-06-24 11:16 ` Dave Martin 2019-06-24 12:59 ` Alexandru Elisei 2019-07-03 12:32 ` Marc Zyngier 2019-06-21 9:37 ` [PATCH 02/59] KVM: arm64: Move __load_guest_stage2 to kvm_mmu.h Marc Zyngier 2019-06-24 11:19 ` Dave Martin 2019-07-03 9:30 ` Marc Zyngier 2019-07-03 16:13 ` Dave Martin 2019-06-21 9:37 ` [PATCH 03/59] arm64: Add ARM64_HAS_NESTED_VIRT cpufeature Marc Zyngier 2019-06-21 13:08 ` Julien Thierry 2019-06-21 13:22 ` Marc Zyngier 2019-06-21 13:44 ` Suzuki K Poulose 2019-06-24 11:24 ` Dave Martin 2019-06-21 9:37 ` [PATCH 04/59] KVM: arm64: nv: Introduce nested virtualization VCPU feature Marc Zyngier 2019-06-21 13:08 ` Julien Thierry 2019-06-24 11:28 ` Dave Martin 2019-07-03 11:53 ` Marc Zyngier 2019-07-03 16:27 ` Dave Martin 2019-06-24 11:43 ` Dave Martin 2019-07-03 11:56 ` Marc Zyngier 2019-07-03 16:24 ` Dave Martin 2019-06-21 9:37 ` [PATCH 05/59] KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set Marc Zyngier 2019-06-24 10:19 ` Suzuki K Poulose 2019-06-24 11:38 ` Dave Martin 2019-06-21 9:37 ` [PATCH 06/59] KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x Marc Zyngier 2019-06-21 13:24 ` Julien Thierry 2019-06-21 13:50 ` Marc Zyngier 2019-06-24 12:48 ` Dave Martin 2019-07-03 9:21 ` Marc Zyngier 2019-07-04 10:00 ` Dave Martin 2019-06-21 9:37 ` [PATCH 07/59] KVM: arm64: nv: Add EL2 system registers to vcpu context Marc Zyngier 2019-06-24 12:54 ` Dave Martin 2019-07-03 12:20 ` Marc Zyngier 2019-07-03 16:31 ` Dave Martin 2019-06-24 15:47 ` Alexandru Elisei 2019-07-03 13:20 ` Marc Zyngier 2019-07-03 16:01 ` Marc Zyngier 2019-07-01 16:36 ` Suzuki K Poulose 2019-06-21 9:37 ` [PATCH 08/59] KVM: arm64: nv: Reset VMPIDR_EL2 and VPIDR_EL2 to sane values Marc Zyngier 2019-06-24 12:59 ` Dave Martin 2019-06-21 9:37 ` [PATCH 09/59] KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state Marc Zyngier 2019-06-24 13:08 ` Dave Martin 2019-06-21 9:37 ` [PATCH 10/59] KVM: arm64: nv: Support virtual EL2 exceptions Marc Zyngier 2019-07-08 13:56 ` Steven Price 2019-06-21 9:37 ` [PATCH 11/59] KVM: arm64: nv: Inject HVC exceptions to the virtual EL2 Marc Zyngier 2019-06-25 13:13 ` Alexandru Elisei 2019-07-03 14:16 ` Marc Zyngier 2019-07-30 14:08 ` Alexandru Elisei 2019-06-21 9:37 ` [PATCH 12/59] KVM: arm64: nv: Handle trapped ERET from " Marc Zyngier 2019-07-02 12:00 ` Alexandru Elisei 2019-06-21 9:37 ` [PATCH 13/59] KVM: arm64: nv: Handle virtual EL2 registers in vcpu_read/write_sys_reg() Marc Zyngier 2019-06-24 12:42 ` Julien Thierry 2019-06-25 14:02 ` Alexandru Elisei 2019-07-03 12:15 ` Marc Zyngier 2019-07-03 15:21 ` Julien Thierry 2019-06-25 15:18 ` Alexandru Elisei 2019-07-01 9:58 ` Alexandru Elisei 2019-07-03 15:59 ` Marc Zyngier 2019-07-03 16:32 ` Alexandru Elisei 2019-07-04 14:39 ` Marc Zyngier 2019-06-26 15:04 ` Alexandru Elisei 2019-07-04 15:05 ` Marc Zyngier 2019-07-01 12:10 ` Alexandru Elisei 2019-06-21 9:37 ` [PATCH 14/59] KVM: arm64: nv: Handle SPSR_EL2 specially Marc Zyngier 2019-06-21 9:37 ` [PATCH 15/59] KVM: arm64: nv: Refactor vcpu_{read,write}_sys_reg Marc Zyngier 2019-06-24 15:07 ` Julien Thierry 2019-07-03 13:09 ` Marc Zyngier 2019-06-27 9:21 ` Alexandru Elisei 2019-07-04 15:15 ` Marc Zyngier 2019-06-21 9:38 ` [PATCH 16/59] KVM: arm64: nv: Save/Restore vEL2 sysregs Marc Zyngier 2019-06-25 8:48 ` Julien Thierry [this message] 2019-07-03 13:42 ` Marc Zyngier 2019-07-01 12:09 ` Alexandru Elisei 2019-08-21 11:57 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 17/59] KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor Marc Zyngier 2019-06-21 9:38 ` [PATCH 18/59] KVM: arm64: nv: Trap EL1 VM register accesses in virtual EL2 Marc Zyngier 2019-07-01 16:12 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 19/59] KVM: arm64: nv: Trap SPSR_EL1, ELR_EL1 and VBAR_EL1 from " Marc Zyngier 2019-06-21 9:38 ` [PATCH 20/59] KVM: arm64: nv: Trap CPACR_EL1 access in " Marc Zyngier 2019-07-01 16:40 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 21/59] KVM: arm64: nv: Set a handler for the system instruction traps Marc Zyngier 2019-06-25 12:55 ` Julien Thierry 2019-07-03 14:15 ` Marc Zyngier 2019-06-21 9:38 ` [PATCH 22/59] KVM: arm64: nv: Handle PSCI call via smc from the guest Marc Zyngier 2019-06-21 9:38 ` [PATCH 23/59] KVM: arm64: nv: Respect virtual HCR_EL2.TWX setting Marc Zyngier 2019-06-25 14:19 ` Julien Thierry 2019-07-02 12:54 ` Alexandru Elisei 2019-07-03 14:18 ` Marc Zyngier 2019-06-21 9:38 ` [PATCH 24/59] KVM: arm64: nv: Respect virtual CPTR_EL2.TFP setting Marc Zyngier 2019-06-21 9:38 ` [PATCH 25/59] KVM: arm64: nv: Don't expose SVE to nested guests Marc Zyngier 2019-06-21 9:38 ` [PATCH 26/59] KVM: arm64: nv: Respect the virtual HCR_EL2.NV bit setting Marc Zyngier 2019-06-26 5:31 ` Julien Thierry 2019-07-03 16:31 ` Marc Zyngier 2019-06-21 9:38 ` [PATCH 27/59] KVM: arm64: nv: Respect virtual HCR_EL2.TVM and TRVM settings Marc Zyngier 2019-06-26 6:55 ` Julien Thierry 2019-07-04 14:57 ` Marc Zyngier 2019-06-21 9:38 ` [PATCH 28/59] KVM: arm64: nv: Respect the virtual HCR_EL2.NV1 bit setting Marc Zyngier 2019-06-26 7:23 ` Julien Thierry 2019-07-02 16:32 ` Alexandru Elisei 2019-07-03 9:10 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 29/59] KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2 Marc Zyngier 2019-07-03 9:16 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 30/59] KVM: arm64: nv: Configure HCR_EL2 for nested virtualization Marc Zyngier 2019-06-21 9:38 ` [PATCH 31/59] KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes Marc Zyngier 2019-06-21 9:38 ` [PATCH 32/59] KVM: arm64: nv: Hide RAS from nested guests Marc Zyngier 2019-07-03 13:59 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 33/59] KVM: arm64: nv: Pretend we only support larger-than-host page sizes Marc Zyngier 2019-07-03 14:13 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 34/59] KVM: arm/arm64: nv: Factor out stage 2 page table data from struct kvm Marc Zyngier 2019-07-03 15:52 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 35/59] KVM: arm/arm64: nv: Support multiple nested stage 2 mmu structures Marc Zyngier 2019-06-25 12:19 ` Alexandru Elisei 2019-07-03 13:47 ` Marc Zyngier 2019-06-27 13:15 ` Julien Thierry 2019-07-04 15:51 ` Alexandru Elisei 2020-01-05 11:35 ` Marc Zyngier 2020-01-06 16:31 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 36/59] KVM: arm64: nv: Implement nested Stage-2 page table walk logic Marc Zyngier 2019-06-21 9:38 ` [PATCH 37/59] KVM: arm64: nv: Handle shadow stage 2 page faults Marc Zyngier 2019-07-05 14:28 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 38/59] KVM: arm64: nv: Unmap/flush shadow stage 2 page tables Marc Zyngier 2019-07-01 8:03 ` Julien Thierry 2019-06-21 9:38 ` [PATCH 39/59] KVM: arm64: nv: Move last_vcpu_ran to be per s2 mmu Marc Zyngier 2019-07-01 9:10 ` Julien Thierry 2019-07-05 15:28 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 40/59] KVM: arm64: nv: Don't always start an S2 MMU search from the beginning Marc Zyngier 2019-07-09 9:59 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 41/59] KVM: arm64: nv: Introduce sys_reg_desc.forward_trap Marc Zyngier 2019-06-21 9:38 ` [PATCH 42/59] KVM: arm64: nv: Rework the system instruction emulation framework Marc Zyngier 2019-06-21 9:38 ` [PATCH 43/59] KVM: arm64: nv: Trap and emulate AT instructions from virtual EL2 Marc Zyngier 2019-07-01 15:45 ` Julien Thierry 2019-07-09 13:20 ` Alexandru Elisei 2019-07-18 12:13 ` Tomasz Nowicki 2019-07-18 12:36 ` Alexandru Elisei 2019-07-18 12:56 ` Alexandru Elisei 2019-07-18 12:59 ` Tomasz Nowicki 2019-07-24 10:25 ` Tomasz Nowicki 2019-07-24 12:39 ` Marc Zyngier 2019-07-24 13:56 ` Tomasz Nowicki 2019-06-21 9:38 ` [PATCH 44/59] KVM: arm64: nv: Trap and emulate TLBI " Marc Zyngier 2019-07-02 12:37 ` Julien Thierry 2019-07-10 10:15 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 45/59] KVM: arm64: nv: Handle traps for timer _EL02 and _EL2 sysregs accessors Marc Zyngier 2019-06-21 9:38 ` [PATCH 46/59] KVM: arm64: nv: arch_timer: Support hyp timer emulation Marc Zyngier 2019-07-10 16:23 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 47/59] KVM: arm64: nv: Propagate CNTVOFF_EL2 to the virtual EL1 timer Marc Zyngier 2019-08-08 9:34 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 48/59] KVM: arm64: nv: Load timer before the GIC Marc Zyngier 2019-07-11 13:17 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 49/59] KVM: arm64: nv: vgic-v3: Take cpu_if pointer directly instead of vcpu Marc Zyngier 2019-06-21 9:38 ` [PATCH 50/59] KVM: arm64: nv: Nested GICv3 Support Marc Zyngier 2019-07-16 11:41 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 51/59] KVM: arm64: nv: vgic: Emulate the HW bit in software Marc Zyngier 2019-06-21 9:38 ` [PATCH 52/59] KVM: arm64: nv: vgic: Allow userland to set VGIC maintenance IRQ Marc Zyngier 2019-07-04 7:38 ` Julien Thierry 2019-07-04 9:01 ` Andre Przywara 2019-07-04 9:04 ` Julien Thierry 2019-06-21 9:38 ` [PATCH 53/59] KVM: arm64: nv: Implement maintenance interrupt forwarding Marc Zyngier 2019-07-04 8:06 ` Julien Thierry 2019-07-16 16:35 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 54/59] KVM: arm64: nv: Add nested GICv3 tracepoints Marc Zyngier 2019-06-21 9:38 ` [PATCH 55/59] arm64: KVM: nv: Add handling of EL2-specific timer registers Marc Zyngier 2019-07-11 12:35 ` Alexandru Elisei 2019-07-17 10:19 ` Alexandru Elisei 2019-06-21 9:38 ` [PATCH 56/59] arm64: KVM: nv: Honor SCTLR_EL2.SPAN on entering vEL2 Marc Zyngier 2019-06-21 9:38 ` [PATCH 57/59] arm64: KVM: nv: Handle SCTLR_EL2 RES0/RES1 bits Marc Zyngier 2019-06-21 9:38 ` [PATCH 58/59] arm64: KVM: nv: Restrict S2 RD/WR permissions to match the guest's Marc Zyngier 2019-06-21 9:38 ` [PATCH 59/59] arm64: KVM: nv: Allow userspace to request KVM_ARM_VCPU_NESTED_VIRT Marc Zyngier 2019-06-21 9:57 ` [PATCH 00/59] KVM: arm64: ARMv8.3 Nested Virtualization support Itaru Kitayama 2019-06-21 11:21 ` Marc Zyngier 2019-08-02 10:11 ` Alexandru Elisei 2019-08-02 10:30 ` Andrew Jones 2019-08-09 10:01 ` Alexandru Elisei 2019-08-09 11:44 ` Andrew Jones 2019-08-09 12:00 ` Alexandru Elisei 2019-08-09 13:00 ` Andrew Jones 2019-08-22 11:57 ` Alexandru Elisei 2019-08-22 15:32 ` Alexandru Elisei
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