| Message ID | 20240821153844.60084-8-steven.price@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Support for Arm CCA in KVM | expand |
On 8/22/24 1:38 AM, Steven Price wrote: > Query the RMI version number and check if it is a compatible version. A > static key is also provided to signal that a supported RMM is available. > > Functions are provided to query if a VM or VCPU is a realm (or rec) > which currently will always return false. > > Signed-off-by: Steven Price <steven.price@arm.com> > --- > Changes since v2: > * Drop return value from kvm_init_rme(), it was always 0. > * Rely on the RMM return value to identify whether the RSI ABI is > compatible. > --- > arch/arm64/include/asm/kvm_emulate.h | 17 +++++++++ > arch/arm64/include/asm/kvm_host.h | 4 ++ > arch/arm64/include/asm/kvm_rme.h | 56 ++++++++++++++++++++++++++++ > arch/arm64/include/asm/virt.h | 1 + > arch/arm64/kvm/Makefile | 3 +- > arch/arm64/kvm/arm.c | 6 +++ > arch/arm64/kvm/rme.c | 50 +++++++++++++++++++++++++ > 7 files changed, 136 insertions(+), 1 deletion(-) > create mode 100644 arch/arm64/include/asm/kvm_rme.h > create mode 100644 arch/arm64/kvm/rme.c > [...] > diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c > new file mode 100644 > index 000000000000..418685fbf6ed > --- /dev/null > +++ b/arch/arm64/kvm/rme.c > @@ -0,0 +1,50 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2023 ARM Ltd. > + */ > + > +#include <linux/kvm_host.h> > + > +#include <asm/rmi_cmds.h> > +#include <asm/virt.h> > + > +static int rmi_check_version(void) > +{ > + struct arm_smccc_res res; > + int version_major, version_minor; > + unsigned long host_version = RMI_ABI_VERSION(RMI_ABI_MAJOR_VERSION, > + RMI_ABI_MINOR_VERSION); > + > + arm_smccc_1_1_invoke(SMC_RMI_VERSION, host_version, &res); > + > + if (res.a0 == SMCCC_RET_NOT_SUPPORTED) > + return -ENXIO; > + > + version_major = RMI_ABI_VERSION_GET_MAJOR(res.a1); > + version_minor = RMI_ABI_VERSION_GET_MINOR(res.a1); > + > + if (res.a0 != RMI_SUCCESS) { > + kvm_err("Unsupported RMI ABI (v%d.%d) host supports v%d.%d\n", > + version_major, version_minor, > + RMI_ABI_MAJOR_VERSION, > + RMI_ABI_MINOR_VERSION); This message is perhaps something like below since a range of versions can be supported by one particular RMM release. kvm_err("Unsupported RMI ABI v%d.%d. Host supports v%ld.%ld - v%ld.%ld\n", RMI_ABI_MAJOR_VERSION, RMI_ABI_MINOR_VERSION, RMI_ABI_VERSION_GET_MAJOR(res.a1), RMI_ABI_VERSION_GET_MINOR(res.a1), RMI_ABI_VERSION_GET_MAJOR(res.a2), RMI_ABI_VERSION_GET_MINOR(res.a2)); > + return -ENXIO; > + } > + > + kvm_info("RMI ABI version %d.%d\n", version_major, version_minor); > + We probably need to print the requested version, instead of the lower implemented version, if I'm correct. At present, both of them have been fixed to v1.0 and we don't have a problem though. kvm_info("RMI ABI version v%d.%d\n", RMI_ABI_MAJOR_VERSION, RMI_ABI_MINOR_VERSION); > + return 0; > +} > + Thanks, Gavin
Hi Gavin, On 12/09/2024 09:49, Gavin Shan wrote: > On 8/22/24 1:38 AM, Steven Price wrote: >> Query the RMI version number and check if it is a compatible version. A >> static key is also provided to signal that a supported RMM is available. >> >> Functions are provided to query if a VM or VCPU is a realm (or rec) >> which currently will always return false. >> >> Signed-off-by: Steven Price <steven.price@arm.com> >> --- >> Changes since v2: >> * Drop return value from kvm_init_rme(), it was always 0. >> * Rely on the RMM return value to identify whether the RSI ABI is >> compatible. >> --- >> arch/arm64/include/asm/kvm_emulate.h | 17 +++++++++ >> arch/arm64/include/asm/kvm_host.h | 4 ++ >> arch/arm64/include/asm/kvm_rme.h | 56 ++++++++++++++++++++++++++++ >> arch/arm64/include/asm/virt.h | 1 + >> arch/arm64/kvm/Makefile | 3 +- >> arch/arm64/kvm/arm.c | 6 +++ >> arch/arm64/kvm/rme.c | 50 +++++++++++++++++++++++++ >> 7 files changed, 136 insertions(+), 1 deletion(-) >> create mode 100644 arch/arm64/include/asm/kvm_rme.h >> create mode 100644 arch/arm64/kvm/rme.c >> > > [...] > >> diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c >> new file mode 100644 >> index 000000000000..418685fbf6ed >> --- /dev/null >> +++ b/arch/arm64/kvm/rme.c >> @@ -0,0 +1,50 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright (C) 2023 ARM Ltd. >> + */ >> + >> +#include <linux/kvm_host.h> >> + >> +#include <asm/rmi_cmds.h> >> +#include <asm/virt.h> >> + >> +static int rmi_check_version(void) >> +{ >> + struct arm_smccc_res res; >> + int version_major, version_minor; >> + unsigned long host_version = RMI_ABI_VERSION(RMI_ABI_MAJOR_VERSION, >> + RMI_ABI_MINOR_VERSION); >> + >> + arm_smccc_1_1_invoke(SMC_RMI_VERSION, host_version, &res); >> + >> + if (res.a0 == SMCCC_RET_NOT_SUPPORTED) >> + return -ENXIO; >> + >> + version_major = RMI_ABI_VERSION_GET_MAJOR(res.a1); >> + version_minor = RMI_ABI_VERSION_GET_MINOR(res.a1); >> + >> + if (res.a0 != RMI_SUCCESS) { >> + kvm_err("Unsupported RMI ABI (v%d.%d) host supports v%d.%d\n", >> + version_major, version_minor, >> + RMI_ABI_MAJOR_VERSION, >> + RMI_ABI_MINOR_VERSION); > > This message is perhaps something like below since a range of versions > can be > supported by one particular RMM release. > > kvm_err("Unsupported RMI ABI v%d.%d. Host supports v%ld.%ld - > v%ld.%ld\n", > RMI_ABI_MAJOR_VERSION, RMI_ABI_MINOR_VERSION, > RMI_ABI_VERSION_GET_MAJOR(res.a1), > RMI_ABI_VERSION_GET_MINOR(res.a1), > RMI_ABI_VERSION_GET_MAJOR(res.a2), > RMI_ABI_VERSION_GET_MINOR(res.a2)); > >> + return -ENXIO; >> + } >> + >> + kvm_info("RMI ABI version %d.%d\n", version_major, version_minor); >> + > > We probably need to print the requested version, instead of the lower > implemented > version, if I'm correct. At present, both of them have been fixed to > v1.0 and we > don't have a problem though. The RSI_VERSION command is somewhat complex. The RMM returns both a "higher revision" and a "lower revision". The higher revision is the highest interface revision supported by the RMM - and not especially useful at least for the moment when Linux is only aiming for v1.0. So we're currently just reporting the "lower revision" in the outputs. There are three possibilities explained in the spec: a) The RMM is compatible (status code is RSI_SUCCESS). From the spec "The lower revision is equal to the requested revision". So this last print will indeed output the requested revision. b) The RMM doesn't support the requested revision, it supports an older revision. In this case "The lower revision is the highest interface revision which is both less than the requested revision and supported by the RMM". Of course when we're requesting v1.0 this situation should never occur, but generally we'd expect to negotiate the lower revision if possible so this is the useful information to output. c) The RMM does not support the requested revision, it supports a newer revision. From the spec "The lower revision is equal to the higher revision". So there's no point outputting both. So situation (b) is the only case where the higher revision is interesting. But it's only useful in a situation like: * Linux supports v1.1 and v2.0 (and maybe v1.0). * Linux prefers v1.1 over v2.0 (and v2.0 over v1.0). * Linux therefore requests v1.1. * The RMM supports v1.0 and v2.0 (but not v1.1) and so returns failure. * lower revision: v1.0 * higher revision: v2.0 Linux can then use the higher revision field to detect that it can try again with v2.0. My expectation is that newer revisions will be preferred and so Linux will always start by requesting the newest revision it supports (so "higher revision" will be irrelevant). But it's there so we can support a scenario like above. We could output the higher revision just for information, a form of "hey, your RMM is newer than Linux" - but I'm not sure I see the point. Steve > kvm_info("RMI ABI version v%d.%d\n", RMI_ABI_MAJOR_VERSION, > RMI_ABI_MINOR_VERSION); > >> + return 0; >> +} >> + > > Thanks, > Gavin >
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index a601a9305b10..c7bfb6788c96 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -693,4 +693,21 @@ static inline bool guest_hyp_sve_traps_enabled(const struct kvm_vcpu *vcpu) return __guest_hyp_cptr_xen_trap_enabled(vcpu, ZEN); } +static inline bool kvm_is_realm(struct kvm *kvm) +{ + if (static_branch_unlikely(&kvm_rme_is_available) && kvm) + return kvm->arch.is_realm; + return false; +} + +static inline enum realm_state kvm_realm_state(struct kvm *kvm) +{ + return READ_ONCE(kvm->arch.realm.state); +} + +static inline bool vcpu_is_rec(struct kvm_vcpu *vcpu) +{ + return false; +} + #endif /* __ARM64_KVM_EMULATE_H__ */ diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index a33f5996ca9f..e36be05b97f8 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -27,6 +27,7 @@ #include <asm/fpsimd.h> #include <asm/kvm.h> #include <asm/kvm_asm.h> +#include <asm/kvm_rme.h> #include <asm/vncr_mapping.h> #define __KVM_HAVE_ARCH_INTC_INITIALIZED @@ -375,6 +376,9 @@ struct kvm_arch { * the associated pKVM instance in the hypervisor. */ struct kvm_protected_vm pkvm; + + bool is_realm; + struct realm realm; }; struct kvm_vcpu_fault_info { diff --git a/arch/arm64/include/asm/kvm_rme.h b/arch/arm64/include/asm/kvm_rme.h new file mode 100644 index 000000000000..69af5c3a1e44 --- /dev/null +++ b/arch/arm64/include/asm/kvm_rme.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2023 ARM Ltd. + */ + +#ifndef __ASM_KVM_RME_H +#define __ASM_KVM_RME_H + +/** + * enum realm_state - State of a Realm + */ +enum realm_state { + /** + * @REALM_STATE_NONE: + * Realm has not yet been created. rmi_realm_create() may be + * called to create the realm. + */ + REALM_STATE_NONE, + /** + * @REALM_STATE_NEW: + * Realm is under construction, not eligible for execution. Pages + * may be populated with rmi_data_create(). + */ + REALM_STATE_NEW, + /** + * @REALM_STATE_ACTIVE: + * Realm has been created and is eligible for execution with + * rmi_rec_enter(). Pages may no longer be populated with + * rmi_data_create(). + */ + REALM_STATE_ACTIVE, + /** + * @REALM_STATE_DYING: + * Realm is in the process of being destroyed or has already been + * destroyed. + */ + REALM_STATE_DYING, + /** + * @REALM_STATE_DEAD: + * Realm has been destroyed. + */ + REALM_STATE_DEAD +}; + +/** + * struct realm - Additional per VM data for a Realm + * + * @state: The lifetime state machine for the realm + */ +struct realm { + enum realm_state state; +}; + +void kvm_init_rme(void); + +#endif diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index ebf4a9f943ed..e45d47156dcf 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -81,6 +81,7 @@ void __hyp_reset_vectors(void); bool is_kvm_arm_initialised(void); DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized); +DECLARE_STATIC_KEY_FALSE(kvm_rme_is_available); static inline bool is_pkvm_initialized(void) { diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index a6497228c5a8..5e79e5eee88d 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -20,7 +20,8 @@ kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ vgic/vgic-v3.o vgic/vgic-v4.o \ vgic/vgic-mmio.o vgic/vgic-mmio-v2.o \ vgic/vgic-mmio-v3.o vgic/vgic-kvm-device.o \ - vgic/vgic-its.o vgic/vgic-debug.o + vgic/vgic-its.o vgic/vgic-debug.o \ + rme.o kvm-$(CONFIG_HW_PERF_EVENTS) += pmu-emul.o pmu.o kvm-$(CONFIG_ARM64_PTR_AUTH) += pauth.o diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index a7ca776b51ec..71ffcc766eeb 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -40,6 +40,7 @@ #include <asm/kvm_nested.h> #include <asm/kvm_pkvm.h> #include <asm/kvm_ptrauth.h> +#include <asm/kvm_rme.h> #include <asm/sections.h> #include <kvm/arm_hypercalls.h> @@ -57,6 +58,8 @@ enum kvm_wfx_trap_policy { static enum kvm_wfx_trap_policy kvm_wfi_trap_policy __read_mostly = KVM_WFX_NOTRAP_SINGLE_TASK; static enum kvm_wfx_trap_policy kvm_wfe_trap_policy __read_mostly = KVM_WFX_NOTRAP_SINGLE_TASK; +DEFINE_STATIC_KEY_FALSE(kvm_rme_is_available); + DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector); DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page); @@ -2788,6 +2791,9 @@ static __init int kvm_arm_init(void) in_hyp_mode = is_kernel_in_hyp_mode(); + if (in_hyp_mode) + kvm_init_rme(); + if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE) || cpus_have_final_cap(ARM64_WORKAROUND_1508412)) kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \ diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c new file mode 100644 index 000000000000..418685fbf6ed --- /dev/null +++ b/arch/arm64/kvm/rme.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 ARM Ltd. + */ + +#include <linux/kvm_host.h> + +#include <asm/rmi_cmds.h> +#include <asm/virt.h> + +static int rmi_check_version(void) +{ + struct arm_smccc_res res; + int version_major, version_minor; + unsigned long host_version = RMI_ABI_VERSION(RMI_ABI_MAJOR_VERSION, + RMI_ABI_MINOR_VERSION); + + arm_smccc_1_1_invoke(SMC_RMI_VERSION, host_version, &res); + + if (res.a0 == SMCCC_RET_NOT_SUPPORTED) + return -ENXIO; + + version_major = RMI_ABI_VERSION_GET_MAJOR(res.a1); + version_minor = RMI_ABI_VERSION_GET_MINOR(res.a1); + + if (res.a0 != RMI_SUCCESS) { + kvm_err("Unsupported RMI ABI (v%d.%d) host supports v%d.%d\n", + version_major, version_minor, + RMI_ABI_MAJOR_VERSION, + RMI_ABI_MINOR_VERSION); + return -ENXIO; + } + + kvm_info("RMI ABI version %d.%d\n", version_major, version_minor); + + return 0; +} + +void kvm_init_rme(void) +{ + if (PAGE_SIZE != SZ_4K) + /* Only 4k page size on the host is supported */ + return; + + if (rmi_check_version()) + /* Continue without realm support */ + return; + + /* Future patch will enable static branch kvm_rme_is_available */ +}
Query the RMI version number and check if it is a compatible version. A static key is also provided to signal that a supported RMM is available. Functions are provided to query if a VM or VCPU is a realm (or rec) which currently will always return false. Signed-off-by: Steven Price <steven.price@arm.com> --- Changes since v2: * Drop return value from kvm_init_rme(), it was always 0. * Rely on the RMM return value to identify whether the RSI ABI is compatible. --- arch/arm64/include/asm/kvm_emulate.h | 17 +++++++++ arch/arm64/include/asm/kvm_host.h | 4 ++ arch/arm64/include/asm/kvm_rme.h | 56 ++++++++++++++++++++++++++++ arch/arm64/include/asm/virt.h | 1 + arch/arm64/kvm/Makefile | 3 +- arch/arm64/kvm/arm.c | 6 +++ arch/arm64/kvm/rme.c | 50 +++++++++++++++++++++++++ 7 files changed, 136 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/kvm_rme.h create mode 100644 arch/arm64/kvm/rme.c