From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-178.mta1.migadu.com (out-178.mta1.migadu.com [95.215.58.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 237371DD541 for ; Mon, 7 Oct 2024 17:46:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728323190; cv=none; b=gArwnpa6GVsTAlJDKNnvI8Q0yymF9ppk6Tw8U6FO+ImTO+JNnr8T7PoFTaDSCTMAPF38caQQG6RidgSzojXZmv9iBfhgJNXgjc63K6yI0ArZ4XL3UpUVrj9Nhgp8KmDAv13cTdWEbeSsS6/335W4wu+bpEjUt7BGAScAzHGHmxg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728323190; c=relaxed/simple; bh=e4ED7eMhwLEprz+yH5iE2yuJjRznwI3qEXTBAiWDmNw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VO/CaknVBMXi/t5nOWVdJlFx6llTeWyNchbJcu+7rjMSM5DauL1dtfChqPPhvK4b9GTTwJQXldOye9B2VtVC+DyTKjMiGMa3t2zrwFfhzBZiGb4PY/MlWiZIt6wtQvLHh49rcEZoML78KY0IJeMOxQ2nOgs8h4nO7ZDUmOoo6no= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=fiZDfDnA; arc=none smtp.client-ip=95.215.58.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="fiZDfDnA" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1728323187; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PA4lwBWIf/gIh9Xu6DlbvTd7C7dOg44cTO8CUxHuJI4=; b=fiZDfDnAs1XvQ5PBcUAdppZcr0lFb5yKx2lolKEnOi4Eef4msJyWgfybgyxPIZ12mPGZgj vTyGlZrI0B28zS+KcrwZUIzHboo2KPnGgnysAn0lpSguke28zOVOvSBMDPPoe6vSpvmTC5 t/I7xhkpuWOaPAjKZWDzkZQAv9hxaNw= From: Oliver Upton To: kvmarm@lists.linux.dev Cc: Marc Zyngier , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Anshuman Khandual , Oliver Upton Subject: [PATCH v3 07/17] KVM: arm64: nv: Reinject traps that take effect in Host EL0 Date: Mon, 7 Oct 2024 17:45:49 +0000 Message-ID: <20241007174559.1830205-8-oliver.upton@linux.dev> In-Reply-To: <20241007174559.1830205-1-oliver.upton@linux.dev> References: <20241007174559.1830205-1-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Wire up the other end of traps that affect host EL0 by actually injecting them into the guest hypervisor. Skip over FGT entirely, as a cursory glance suggests no FGT is effective in host EL0. Note that kvm_inject_nested() is already equipped for handling exceptions while the VM is already in a host context. Signed-off-by: Oliver Upton --- arch/arm64/include/asm/kvm_emulate.h | 5 +++++ arch/arm64/kvm/emulate-nested.c | 29 ++++++++++++++++++++++++---- 2 files changed, 30 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index a601a9305b10..bf0c48403f59 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -225,6 +225,11 @@ static inline bool is_hyp_ctxt(const struct kvm_vcpu *vcpu) return vcpu_has_nv(vcpu) && __is_hyp_ctxt(&vcpu->arch.ctxt); } +static inline bool vcpu_is_host_el0(const struct kvm_vcpu *vcpu) +{ + return is_hyp_ctxt(vcpu) && !vcpu_is_el2(vcpu); +} + /* * The layout of SPSR for an AArch32 state is different when observed from an * AArch64 SPSR_ELx or an AArch32 SPSR_*. This function generates the AArch32 diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c index e1a30d1bcd06..db3149379a4d 100644 --- a/arch/arm64/kvm/emulate-nested.c +++ b/arch/arm64/kvm/emulate-nested.c @@ -20,6 +20,9 @@ enum trap_behaviour { BEHAVE_FORWARD_READ = BIT(0), BEHAVE_FORWARD_WRITE = BIT(1), BEHAVE_FORWARD_RW = BEHAVE_FORWARD_READ | BEHAVE_FORWARD_WRITE, + + /* Traps that take effect in Host EL0, this is rare! */ + BEHAVE_IN_HOST_EL0 = BIT(2), }; struct trap_bits { @@ -2128,11 +2131,19 @@ static u64 kvm_get_sysreg_res0(struct kvm *kvm, enum vcpu_sysreg sr) return masks->mask[sr - __VNCR_START__].res0; } -static bool check_fgt_bit(struct kvm *kvm, bool is_read, +static bool check_fgt_bit(struct kvm_vcpu *vcpu, bool is_read, u64 val, const union trap_config tc) { + struct kvm *kvm = vcpu->kvm; enum vcpu_sysreg sr; + /* + * KVM doesn't know about any FGTs that apply to the host, and hopefully + * that'll remain the case. + */ + if (is_hyp_ctxt(vcpu)) + return false; + if (tc.pol) return (val & BIT(tc.bit)); @@ -2209,7 +2220,15 @@ bool triage_sysreg_trap(struct kvm_vcpu *vcpu, int *sr_index) * If we're not nesting, immediately return to the caller, with the * sysreg index, should we have it. */ - if (!vcpu_has_nv(vcpu) || is_hyp_ctxt(vcpu)) + if (!vcpu_has_nv(vcpu)) + goto local; + + /* + * There are a few traps that take effect InHost, but are constrained + * to EL0. Don't bother with computing the trap behaviour if the vCPU + * isn't in EL0. + */ + if (is_hyp_ctxt(vcpu) && !vcpu_is_host_el0(vcpu)) goto local; switch ((enum fgt_group_id)tc.fgt) { @@ -2255,12 +2274,14 @@ bool triage_sysreg_trap(struct kvm_vcpu *vcpu, int *sr_index) goto local; } - if (tc.fgt != __NO_FGT_GROUP__ && check_fgt_bit(vcpu->kvm, is_read, - val, tc)) + if (tc.fgt != __NO_FGT_GROUP__ && check_fgt_bit(vcpu, is_read, val, tc)) goto inject; b = compute_trap_behaviour(vcpu, tc); + if (!(b & BEHAVE_IN_HOST_EL0) && vcpu_is_host_el0(vcpu)) + goto local; + if (((b & BEHAVE_FORWARD_READ) && is_read) || ((b & BEHAVE_FORWARD_WRITE) && !is_read)) goto inject; -- 2.47.0.rc0.187.ge670bccf7e-goog