From dea8ee31a039277576c215fffa13957970246366 Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Mon, 27 Sep 2021 17:10:14 +0530 Subject: RISC-V: KVM: Add SBI v0.1 support The KVM host kernel is running in HS-mode needs so we need to handle the SBI calls coming from guest kernel running in VS-mode. This patch adds SBI v0.1 support in KVM RISC-V. Almost all SBI v0.1 calls are implemented in KVM kernel module except GETCHAR and PUTCHART calls which are forwarded to user space because these calls cannot be implemented in kernel space. In future, when we implement SBI v0.2 for Guest, we will forward SBI v0.2 experimental and vendor extension calls to user space. Signed-off-by: Atish Patra Signed-off-by: Anup Patel Acked-by: Paolo Bonzini Reviewed-by: Paolo Bonzini Acked-by: Palmer Dabbelt --- include/uapi/linux/kvm.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index a067410ebea5..322b4b588d75 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -269,6 +269,7 @@ struct kvm_xen_exit { #define KVM_EXIT_AP_RESET_HOLD 32 #define KVM_EXIT_X86_BUS_LOCK 33 #define KVM_EXIT_XEN 34 +#define KVM_EXIT_RISCV_SBI 35 /* For KVM_EXIT_INTERNAL_ERROR */ /* Emulate instruction failed. */ @@ -469,6 +470,13 @@ struct kvm_run { } msr; /* KVM_EXIT_XEN */ struct kvm_xen_exit xen; + /* KVM_EXIT_RISCV_SBI */ + struct { + unsigned long extension_id; + unsigned long function_id; + unsigned long args[6]; + unsigned long ret[2]; + } riscv_sbi; /* Fix the size of the union. */ char padding[256]; }; -- cgit v1.2.3 From c68dc1b577eabd5605c6c7c08f3e07ae18d30d5d Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Thu, 16 Sep 2021 18:15:35 +0000 Subject: KVM: x86: Report host tsc and realtime values in KVM_GET_CLOCK Handling the migration of TSCs correctly is difficult, in part because Linux does not provide userspace with the ability to retrieve a (TSC, realtime) clock pair for a single instant in time. In lieu of a more convenient facility, KVM can report similar information in the kvm_clock structure. Provide userspace with a host TSC & realtime pair iff the realtime clock is based on the TSC. If userspace provides KVM_SET_CLOCK with a valid realtime value, advance the KVM clock by the amount of elapsed time. Do not step the KVM clock backwards, though, as it is a monotonic oscillator. Suggested-by: Paolo Bonzini Signed-off-by: Oliver Upton Signed-off-by: Paolo Bonzini Message-Id: <20210916181538.968978-5-oupton@google.com> Signed-off-by: Paolo Bonzini --- include/uapi/linux/kvm.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 322b4b588d75..5ca5ffe16cb4 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1231,11 +1231,16 @@ struct kvm_irqfd { /* Do not use 1, KVM_CHECK_EXTENSION returned it before we had flags. */ #define KVM_CLOCK_TSC_STABLE 2 +#define KVM_CLOCK_REALTIME (1 << 2) +#define KVM_CLOCK_HOST_TSC (1 << 3) struct kvm_clock_data { __u64 clock; __u32 flags; - __u32 pad[9]; + __u32 pad0; + __u64 realtime; + __u64 host_tsc; + __u32 pad[4]; }; /* For KVM_CAP_SW_TLB */ -- cgit v1.2.3 From a9d496d8e08ca1eb43d14cb734839b24ab0e8083 Mon Sep 17 00:00:00 2001 From: David Edmondson Date: Mon, 20 Sep 2021 11:37:34 +0100 Subject: KVM: x86: Clarify the kvm_run.emulation_failure structure layout Until more flags for kvm_run.emulation_failure flags are defined, it is undetermined whether new payload elements corresponding to those flags will be additive or alternative. As a hint to userspace that an alternative is possible, wrap the current payload elements in a union. Suggested-by: Sean Christopherson Signed-off-by: David Edmondson Reviewed-by: Sean Christopherson Message-Id: <20210920103737.2696756-2-david.edmondson@oracle.com> Signed-off-by: Paolo Bonzini --- include/uapi/linux/kvm.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 5ca5ffe16cb4..2c8aa8d4dac1 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -403,8 +403,12 @@ struct kvm_run { __u32 suberror; __u32 ndata; __u64 flags; - __u8 insn_size; - __u8 insn_bytes[15]; + union { + struct { + __u8 insn_size; + __u8 insn_bytes[15]; + }; + }; } emulation_failure; /* KVM_EXIT_OSI */ struct { -- cgit v1.2.3 From e615e355894e619785af81479ad6f5a05a8a2e3f Mon Sep 17 00:00:00 2001 From: David Edmondson Date: Mon, 20 Sep 2021 11:37:36 +0100 Subject: KVM: x86: On emulation failure, convey the exit reason, etc. to userspace Should instruction emulation fail, include the VM exit reason, etc. in the emulation_failure data passed to userspace, in order that the VMM can report it as a debugging aid when describing the failure. Suggested-by: Joao Martins Signed-off-by: David Edmondson Reviewed-by: Sean Christopherson Message-Id: <20210920103737.2696756-4-david.edmondson@oracle.com> Signed-off-by: Paolo Bonzini --- include/uapi/linux/kvm.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 2c8aa8d4dac1..78f0719cc2a3 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -398,6 +398,11 @@ struct kvm_run { * "ndata" is correct, that new fields are enumerated in "flags", * and that each flag enumerates fields that are 64-bit aligned * and sized (so that ndata+internal.data[] is valid/accurate). + * + * Space beyond the defined fields may be used to store arbitrary + * debug information relating to the emulation failure. It is + * accounted for in "ndata" but the format is unspecified and is + * not represented in "flags". Any such information is *not* ABI! */ struct { __u32 suberror; @@ -409,6 +414,7 @@ struct kvm_run { __u8 insn_bytes[15]; }; }; + /* Arbitrary debug data may follow. */ } emulation_failure; /* KVM_EXIT_OSI */ struct { -- cgit v1.2.3