Hello, Le 30/12/2025 à 16:52, Oleksii Kurochko a écrit : > Add support of virtual SBI base extension calls for RISC-V guests, delegating > hardware-specific queries to the underlying SBI and handling version and > firmware ID queries directly. > > The changes include: > 1. Define new SBI base extension function IDs (SBI_EXT_BASE_GET_MVENDORID, > SBI_EXT_BASE_GET_MARCHID, SBI_EXT_BASE_GET_MIMPID). > 2. Introduce XEN_SBI_VER_MAJOR, XEN_SBI_VER_MINOR for imeplenataion of > SBI_EXT_BASE_GET_SPEC_VERSION. > 4. Introduce SBI_XEN_IMPID to implement SBI_EXT_BASE_GET_IMP_ID. > 5. Implement handling of SBI base extension functions, including version, > firmware ID, and machine-specific queries. > > Signed-off-by: Oleksii Kurochko <[email protected]> > --- > Changes in v4: > - Move definition of XEN_SBI_VER_{MAJOR, MINOR} to base-extension.c. > - Correct string format for FID: s/#%#lx/#%lu. > - Print first EID then FID (as vsbi/core.c code does). > --- > Changes in v3: > - s/XEN_SBI_IMPID/SBI_XEN_IMPID > - Add ASSERT(eid == SBI_EXT_BASE) in vsbi_base_ecall_handler(). > - Fix code style for switch/case. > - Use current instead of `vcpu` argument as it was dropped from > vsbi_base_ecall_handler() prototype. > - Add comments for define-s XEN_SBI_VER_{MAJOR, MINOR} and SBI_XEN_IMPID. > --- > Changes in v2: > - s/vsbi-base-extension.*/base-extension.* > - Introduce VCPU_SBI_IMPID, XEN_SBI_VER_MINOR and XEN_SBI_VER_MAJOR. > - Return VCPU_SBI_IMPID in the case of SBI_EXT_BASE_GET_IMP_ID. > - Return Xen version in the case of SBI_EXT_BASE_GET_IMP_VERSION. > - Use domain_crash() instead of panic() for default case. > - For SBI_EXT_BASE_GET_{MVENDORID,MARCHID,MIMPID} abd SBI_EXT_BASE_PROBE_EXT > add handling of a domain is h/w or not. > --- > xen/arch/riscv/include/asm/sbi.h | 6 ++ > xen/arch/riscv/vsbi/Makefile | 1 + > xen/arch/riscv/vsbi/base-extension.c | 82 ++++++++++++++++++++++++++++ > 3 files changed, 89 insertions(+) > create mode 100644 xen/arch/riscv/vsbi/base-extension.c > > diff --git a/xen/arch/riscv/include/asm/sbi.h > b/xen/arch/riscv/include/asm/sbi.h > index 751bae6d6654..79f7ff5c5501 100644 > --- a/xen/arch/riscv/include/asm/sbi.h > +++ b/xen/arch/riscv/include/asm/sbi.h > @@ -14,6 +14,9 @@ > > #include <xen/cpumask.h> > > +/* SBI-defined implementation ID */ > +#define SBI_XEN_IMPID 7 > + > #define SBI_EXT_0_1_SET_TIMER 0x0 > #define SBI_EXT_0_1_CONSOLE_PUTCHAR 0x1 > #define SBI_EXT_0_1_CONSOLE_GETCHAR 0x2 > @@ -32,6 +35,9 @@ > #define SBI_EXT_BASE_GET_IMP_ID 0x1 > #define SBI_EXT_BASE_GET_IMP_VERSION 0x2 > #define SBI_EXT_BASE_PROBE_EXT 0x3 > +#define SBI_EXT_BASE_GET_MVENDORID 0x4 > +#define SBI_EXT_BASE_GET_MARCHID 0x5 > +#define SBI_EXT_BASE_GET_MIMPID 0x6 > > /* SBI function IDs for RFENCE extension */ > #define SBI_EXT_RFENCE_REMOTE_FENCE_I 0x0 > diff --git a/xen/arch/riscv/vsbi/Makefile b/xen/arch/riscv/vsbi/Makefile > index bc5755cb13d6..8ce470f787c5 100644 > --- a/xen/arch/riscv/vsbi/Makefile > +++ b/xen/arch/riscv/vsbi/Makefile > @@ -1,2 +1,3 @@ > +obj-y += base-extension.o > obj-y += core.o > obj-y += legacy-extension.o > diff --git a/xen/arch/riscv/vsbi/base-extension.c > b/xen/arch/riscv/vsbi/base-extension.c > new file mode 100644 > index 000000000000..41a95ae188dd > --- /dev/null > +++ b/xen/arch/riscv/vsbi/base-extension.c > @@ -0,0 +1,82 @@ > + > +/* SPDX-License-Identifier: GPL-2.0-only */ > + > +#include <xen/lib.h> > +#include <xen/sched.h> > +#include <xen/version.h> > + > +#include <asm/processor.h> > +#include <asm/sbi.h> > +#include <asm/vsbi.h> > + > +/* Xen-controlled SBI version reported to guests */ > +#define XEN_SBI_VER_MAJOR 0 > +#define XEN_SBI_VER_MINOR 2 > + > +static int vsbi_base_ecall_handler(unsigned long eid, unsigned long fid, > + struct cpu_user_regs *regs) > +{ > + int ret = 0; > + struct sbiret sbi_ret; > + > + ASSERT(eid == SBI_EXT_BASE); > + > + switch ( fid ) > + { > + case SBI_EXT_BASE_GET_SPEC_VERSION: > + regs->a1 = MASK_INSR(XEN_SBI_VER_MAJOR, SBI_SPEC_VERSION_MAJOR_MASK) > | > + XEN_SBI_VER_MINOR; > + break; > + > + case SBI_EXT_BASE_GET_IMP_ID: > + regs->a1 = SBI_XEN_IMPID; > + break; > + > + case SBI_EXT_BASE_GET_IMP_VERSION: > + regs->a1 = (xen_major_version() << 16) | xen_minor_version(); > + break; > + > + case SBI_EXT_BASE_GET_MVENDORID: > + case SBI_EXT_BASE_GET_MARCHID: > + case SBI_EXT_BASE_GET_MIMPID: > + if ( is_hardware_domain(current->domain) ) > + { > + sbi_ret = sbi_ecall(SBI_EXT_BASE, fid, 0, 0, 0, 0, 0, 0); > + ret = sbi_ret.error; > + regs->a1 = sbi_ret.value; > + } > + else > + /* > + * vSBI should present a consistent, virtualized view to guests. > + * In particular, DomU-visible data must remain stable across > + * migration and must not expose hardware-specific details. > + * > + * These register(s) must be readable in any implementation, > + * but a value of 0 can be returned to indicate the field > + * is not implemented. > + */ > + regs->a1 = 0; > + > + break; > + > + case SBI_EXT_BASE_PROBE_EXT: > + regs->a1 = vsbi_find_extension(regs->a0) ? 1 : 0; > + break; > + > + default: > + /* > + * TODO: domain_crash() is acceptable here while things are still > under > + * development. > + * It shouldn't stay like this in the end though: guests should not > + * be punished like this for something Xen hasn't implemented. > + */ > + domain_crash(current->domain, > + "%s: Unsupported ecall: EID: #%#lx FID: #%lu\n", > + __func__, eid, fid);
I think we should rather report "SBI_ERR_NOT_SUPPORTED" (-2) instead (eventually logging a warning in Xen) ? > + break; > + } > + > + return ret; > +} > + > +VSBI_EXT(base, SBI_EXT_BASE, SBI_EXT_BASE, vsbi_base_ecall_handler) Teddy -- Teddy Astie | Vates XCP-ng Developer XCP-ng & Xen Orchestra - Vates solutions web: https://vates.tech
