From: Dave Martin <Dave.Martin@arm.com> To: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org, Andre Przywara <andre.przywara@arm.com>, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: Re: [PATCH 07/59] KVM: arm64: nv: Add EL2 system registers to vcpu context Date: Wed, 3 Jul 2019 17:31:11 +0100 Message-ID: <20190703163111.GW2790@e103592.cambridge.arm.com> (raw) In-Reply-To: <bf624c54-41f6-85d0-e8c1-7943e065ec98@arm.com> On Wed, Jul 03, 2019 at 01:20:55PM +0100, Marc Zyngier wrote: > On 24/06/2019 13:54, Dave Martin wrote: > > On Fri, Jun 21, 2019 at 10:37:51AM +0100, Marc Zyngier wrote: > >> From: Jintack Lim <jintack.lim@linaro.org> > >> > >> ARM v8.3 introduces a new bit in the HCR_EL2, which is the NV bit. When > >> this bit is set, accessing EL2 registers in EL1 traps to EL2. In > >> addition, executing the following instructions in EL1 will trap to EL2: > >> tlbi, at, eret, and msr/mrs instructions to access SP_EL1. Most of the > >> instructions that trap to EL2 with the NV bit were undef at EL1 prior to > >> ARM v8.3. The only instruction that was not undef is eret. > >> > >> This patch sets up a handler for EL2 registers and SP_EL1 register > >> accesses at EL1. The host hypervisor keeps those register values in > >> memory, and will emulate their behavior. > >> > >> This patch doesn't set the NV bit yet. It will be set in a later patch > >> once nested virtualization support is completed. > >> > >> Signed-off-by: Jintack Lim <jintack.lim@linaro.org> > >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > >> --- > >> arch/arm64/include/asm/kvm_host.h | 37 +++++++++++++++- > >> arch/arm64/include/asm/sysreg.h | 50 ++++++++++++++++++++- > >> arch/arm64/kvm/sys_regs.c | 74 ++++++++++++++++++++++++++++--- > >> 3 files changed, 154 insertions(+), 7 deletions(-) > >> > >> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > >> index 4bcd9c1291d5..2d4290d2513a 100644 > >> --- a/arch/arm64/include/asm/kvm_host.h > >> +++ b/arch/arm64/include/asm/kvm_host.h > >> @@ -173,12 +173,47 @@ enum vcpu_sysreg { > >> APGAKEYLO_EL1, > >> APGAKEYHI_EL1, > >> > >> - /* 32bit specific registers. Keep them at the end of the range */ > >> + /* 32bit specific registers. */ > > > > Out of interest, why did we originally want these to be at the end? > > Because they're not at the end any more... > > I seem to remember the original assembly switch code used that property. > This is a long gone requirement, thankfully. Ah, right. > >> DACR32_EL2, /* Domain Access Control Register */ > >> IFSR32_EL2, /* Instruction Fault Status Register */ > >> FPEXC32_EL2, /* Floating-Point Exception Control Register */ > >> DBGVCR32_EL2, /* Debug Vector Catch Register */ > >> > >> + /* EL2 registers sorted ascending by Op0, Op1, CRn, CRm, Op2 */ > >> + FIRST_EL2_SYSREG, > >> + VPIDR_EL2 = FIRST_EL2_SYSREG, > >> + /* Virtualization Processor ID Register */ > >> + VMPIDR_EL2, /* Virtualization Multiprocessor ID Register */ > >> + SCTLR_EL2, /* System Control Register (EL2) */ > >> + ACTLR_EL2, /* Auxiliary Control Register (EL2) */ > >> + HCR_EL2, /* Hypervisor Configuration Register */ > >> + MDCR_EL2, /* Monitor Debug Configuration Register (EL2) */ > >> + CPTR_EL2, /* Architectural Feature Trap Register (EL2) */ > >> + HSTR_EL2, /* Hypervisor System Trap Register */ > >> + HACR_EL2, /* Hypervisor Auxiliary Control Register */ > >> + TTBR0_EL2, /* Translation Table Base Register 0 (EL2) */ > >> + TTBR1_EL2, /* Translation Table Base Register 1 (EL2) */ > >> + TCR_EL2, /* Translation Control Register (EL2) */ > >> + VTTBR_EL2, /* Virtualization Translation Table Base Register */ > >> + VTCR_EL2, /* Virtualization Translation Control Register */ > >> + SPSR_EL2, /* EL2 saved program status register */ > >> + ELR_EL2, /* EL2 exception link register */ > >> + AFSR0_EL2, /* Auxiliary Fault Status Register 0 (EL2) */ > >> + AFSR1_EL2, /* Auxiliary Fault Status Register 1 (EL2) */ > >> + ESR_EL2, /* Exception Syndrome Register (EL2) */ > >> + FAR_EL2, /* Hypervisor IPA Fault Address Register */ > >> + HPFAR_EL2, /* Hypervisor IPA Fault Address Register */ > >> + MAIR_EL2, /* Memory Attribute Indirection Register (EL2) */ > >> + AMAIR_EL2, /* Auxiliary Memory Attribute Indirection Register (EL2) */ > >> + VBAR_EL2, /* Vector Base Address Register (EL2) */ > >> + RVBAR_EL2, /* Reset Vector Base Address Register */ > >> + RMR_EL2, /* Reset Management Register */ > >> + CONTEXTIDR_EL2, /* Context ID Register (EL2) */ > >> + TPIDR_EL2, /* EL2 Software Thread ID Register */ > >> + CNTVOFF_EL2, /* Counter-timer Virtual Offset register */ > >> + CNTHCTL_EL2, /* Counter-timer Hypervisor Control register */ > >> + SP_EL2, /* EL2 Stack Pointer */ > >> + > > > > I wonder whether we could make these conditionally present somehow. Not > > worth worrying about for now to save 200-odd bytes per vcpu though. > > With 8.4-NV, these 200 bytes turn into a whole 8kB (4kB page, plus > almost 4kB of padding that I need to reduce one way or another). So I'm > not too worried about this for now. > > I really want the NV code to always be present though, in order to avoid > configuration related regressions. I'm not sure how to make this better. Fair enough -- sounds like addressing this would probably be premature optimisation, then. I suppose we could have two alternate layouts, but would likely be a source of overhead, and bugs... Cheers ---Dave _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
next prev parent reply index 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 [this message] 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 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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