linux-kernel - [PATCH v2] Support runtime configuration for per-VM's HGATP mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20260105143232.76715-1-fangyu.yu@linux.alibaba.com>
Date: Mon,  5 Jan 2026 22:32:30 +0800
From: fangyu.yu@...ux.alibaba.com
To: pbonzini@...hat.com,
	corbet@....net,
	anup@...infault.org,
	atish.patra@...ux.dev,
	pjw@...nel.org,
	palmer@...belt.com,
	aou@...s.berkeley.edu,
	alex@...ti.fr
Cc: guoren@...nel.org,
	ajones@...tanamicro.com,
	rkrcmar@...tanamicro.com,
	linux-doc@...r.kernel.org,
	kvm@...r.kernel.org,
	kvm-riscv@...ts.infradead.org,
	linux-riscv@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	Fangyu Yu <fangyu.yu@...ux.alibaba.com>
Subject: [PATCH v2] Support runtime configuration for per-VM's HGATP mode

From: Fangyu Yu <fangyu.yu@...ux.alibaba.com>

Currently, RISC-V KVM hardcodes the G-stage page table format (HGATP mode)
to the maximum mode detected at boot time (e.g., SV57x4 if supported). but
often such a wide GPA is unnecessary, just as a host sometimes doesn't need
sv57.

This patch introduces per-VM configurability of the G-stage mode via a new
KVM capability: KVM_CAP_RISCV_SET_HGATP_MODE. User-space can now explicitly
request a specific HGATP mode (SV39x4, SV48x4, or SV57x4 on 64-bit) during
VM creation.

Fangyu Yu (2):
  RISC-V: KVM: Support runtime configuration for per-VM's HGATP mode
  RISC-V: KVM: add KVM_CAP_RISCV_SET_HGATP_MODE

 Documentation/virt/kvm/api.rst      | 14 +++++
 arch/riscv/include/asm/kvm_gstage.h | 12 ++---
 arch/riscv/include/asm/kvm_host.h   |  4 ++
 arch/riscv/kvm/gstage.c             | 82 +++++++++++++++++------------
 arch/riscv/kvm/main.c               |  4 +-
 arch/riscv/kvm/mmu.c                | 18 +++++--
 arch/riscv/kvm/vm.c                 | 28 ++++++++--
 arch/riscv/kvm/vmid.c               |  2 +-
 include/uapi/linux/kvm.h            |  1 +
 9 files changed, 113 insertions(+), 52 deletions(-)

-- 
2.50.1