From: Wang Yechao Date: Mon, 30 Mar 2026 08:10:52 +0000 (+0800) Subject: RISC-V: KVM: Fix lost write protection on huge pages during dirty logging X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a216e24fc947573bfbd56471bd7c1f1d8c7a2b19;p=thirdparty%2Fkernel%2Fstable.git RISC-V: KVM: Fix lost write protection on huge pages during dirty logging When enabling dirty log in small chunks (e.g., QEMU default chunk size of 256K), the chunk size is always smaller than the page size of huge pages (1G or 2M) used in the gstage page tables. This caused the write protection to be incorrectly skipped for huge PTEs because the condition `(end - addr) >= page_size` was not satisfied. Remove the size check in `kvm_riscv_gstage_wp_range()` to ensure huge PTEs are always write-protected regardless of the chunk size. Additionally, explicitly align the address down to the page size before invoking `kvm_riscv_gstage_op_pte()` to guarantee that the address passed to the operation function is page-aligned. This fixes the issue where dirty pages might not be tracked correctly when using huge pages. Fixes: 9d05c1fee837 ("RISC-V: KVM: Implement stage2 page table programming") Signed-off-by: Wang Yechao Reviewed-by: Nutty Liu Reviewed-by: Anup Patel Link: https://lore.kernel.org/r/202603301610527120YZ-pAJY6x9SBpSRo1Wg4@zte.com.cn Signed-off-by: Anup Patel --- diff --git a/arch/riscv/kvm/gstage.c b/arch/riscv/kvm/gstage.c index b67d60d722c2..d2001d508046 100644 --- a/arch/riscv/kvm/gstage.c +++ b/arch/riscv/kvm/gstage.c @@ -304,10 +304,9 @@ void kvm_riscv_gstage_wp_range(struct kvm_gstage *gstage, gpa_t start, gpa_t end if (!found_leaf) goto next; - if (!(addr & (page_size - 1)) && ((end - addr) >= page_size)) - kvm_riscv_gstage_op_pte(gstage, addr, ptep, - ptep_level, GSTAGE_OP_WP); - + addr = ALIGN_DOWN(addr, page_size); + kvm_riscv_gstage_op_pte(gstage, addr, ptep, + ptep_level, GSTAGE_OP_WP); next: addr += page_size; }