From 596289fe4836067b0320c80a9ab0101b9f7f9328 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Tue, 21 Jul 2026 17:16:24 +0100 Subject: [PATCH] KVM: arm64: Sync SCTLR_EL1 when injecting an exception into a pVM When pKVM injects a synchronous exception into a protected guest, enter_exception64() reads SCTLR_EL1 to set the new PSTATE's PAN and SSBS bits. pKVM refreshes VBAR_EL1 from the live value before injecting but not SCTLR_EL1, which is untrapped for protected guests, so a guest that updates it and then traps takes the exception with stale PAN/SSBS. Sync SCTLR_EL1 alongside VBAR_EL1. Fixes: 798eb5978700 ("KVM: arm64: Sync protected guest VBAR_EL1 on injecting an undef exception") Signed-off-by: Fuad Tabba Link: https://patch.msgid.link/20260721161624.3983041-1-fuad.tabba@linux.dev Signed-off-by: Oliver Upton --- arch/arm64/kvm/hyp/nvhe/sys_regs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c index 8c3fbb413a06..7608cc4030b8 100644 --- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c @@ -257,10 +257,11 @@ static void inject_sync64(struct kvm_vcpu *vcpu, u64 esr) *vcpu_cpsr(vcpu) = read_sysreg_el2(SYS_SPSR); /* - * Make sure we have the latest update to VBAR_EL1, as pKVM - * handles traps very early, before sysregs are resync'ed + * Sync VBAR_EL1 and SCTLR_EL1, both read by enter_exception64(), + * as pKVM handles traps before sysregs are resync'ed. */ __vcpu_assign_sys_reg(vcpu, VBAR_EL1, read_sysreg_el1(SYS_VBAR)); + __vcpu_assign_sys_reg(vcpu, SCTLR_EL1, read_sysreg_el1(SYS_SCTLR)); kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);