From nobody Mon Feb 9 05:43:48 2026 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 957EE3126CD; Tue, 27 Jan 2026 12:51:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769518293; cv=none; b=pcwA3VGO9siw2N4yzBu5UqWGQ33SAxn/z0XpCI4HAny31u5bUqmnTcUqGroTRunVvgVCbZzjH7d9c8YZZoq9Adz+GyoaELnFfeBUvlJhkPzIFzKvlmukJZ7Y7YUqfcqPsWFT1EhbO7IxwUuWMQ5sFyOOkgMA/HpxpRRFsAcPxWI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769518293; c=relaxed/simple; bh=soXzKnhsQjPTTL1KYho9t5jG3TgZArfa21WuREO0/D0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=g4EQnJGJ+ndWCzxEeVacfHGAM78Vc3xJq0X5v3K5Mqoc5VaWVoCQGVZRDN4e+uTlWHtTWXRNLGJMCu97y4N14jDnzDcoQ5jRkWLBVJ5yaZ/d0JFjaktj7aDZidaTZXtqbUEPjHtYRSxtfJugC9KCKM0J0qaWz6IGQnFyoKEcP34= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [10.2.5.213]) by gateway (Coremail) with SMTP id _____8AxEvHOtHhpLR4NAA--.43402S3; Tue, 27 Jan 2026 20:51:26 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.5.213]) by front1 (Coremail) with SMTP id qMiowJAxWcHMtHhpYpo0AA--.24006S3; Tue, 27 Jan 2026 20:51:25 +0800 (CST) From: Bibo Mao To: Huacai Chen , WANG Xuerui , Tianrui Zhao Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: [PATCH v2 1/3] LoongArch: KVM: Move LSX capability check in LSX exception handler Date: Tue, 27 Jan 2026 20:51:22 +0800 Message-Id: <20260127125124.3234252-2-maobibo@loongson.cn> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20260127125124.3234252-1-maobibo@loongson.cn> References: <20260127125124.3234252-1-maobibo@loongson.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: qMiowJAxWcHMtHhpYpo0AA--.24006S3 X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ X-Coremail-Antispam: 1Uk129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7 ZEXasCq-sGcSsGvfJ3UbIjqfuFe4nvWSU5nxnvy29KBjDU0xBIdaVrnUUvcSsGvfC2Kfnx nUUI43ZEXa7xR_UUUUUUUUU== Content-Type: text/plain; charset="utf-8" Like FPU exception handler, check LSX capability in LSX exception handler rather than kvm_own_lsx(). LSX capability in function kvm_guest_has_lsx() implies FPU capability in kvm_guest_has_fpu(), only check kvm_guest_has_lsx() is ok here. Signed-off-by: Bibo Mao --- arch/loongarch/kvm/exit.c | 4 +++- arch/loongarch/kvm/vcpu.c | 3 --- 2 files changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c index cb493980d874..76eec3f24953 100644 --- a/arch/loongarch/kvm/exit.c +++ b/arch/loongarch/kvm/exit.c @@ -792,8 +792,10 @@ static long kvm_save_notify(struct kvm_vcpu *vcpu) */ static int kvm_handle_lsx_disabled(struct kvm_vcpu *vcpu, int ecode) { - if (kvm_own_lsx(vcpu)) + if (!kvm_guest_has_lsx(&vcpu->arch)) kvm_queue_exception(vcpu, EXCCODE_INE, 0); + else + kvm_own_lsx(vcpu); =20 return RESUME_GUEST; } diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c index 656b954c1134..aff295aa6b0b 100644 --- a/arch/loongarch/kvm/vcpu.c +++ b/arch/loongarch/kvm/vcpu.c @@ -1358,9 +1358,6 @@ void kvm_own_fpu(struct kvm_vcpu *vcpu) /* Enable LSX and restore context */ int kvm_own_lsx(struct kvm_vcpu *vcpu) { - if (!kvm_guest_has_fpu(&vcpu->arch) || !kvm_guest_has_lsx(&vcpu->arch)) - return -EINVAL; - preempt_disable(); =20 /* Enable LSX for guest */ --=20 2.39.3 From nobody Mon Feb 9 05:43:48 2026 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4C99C2FD69E; Tue, 27 Jan 2026 12:51:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769518294; cv=none; b=PuI0798of1iPValB0Y2CTRobyVC4WDnXTG5MpTmnxAeXnMNpC+npcGt+kYML/w9fwcpJ4nFArwVGYuOBSwSgoreNJsGqGpJ2jibvt4fIGAWblXLghm/vjvzUQH7U99VZlwPluEnVKImXAjsUdzcUt2ZcFnStxsinrITYY+5v5s0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769518294; c=relaxed/simple; bh=IdLW44VGZExsGvqUufz+gqPKgso8L+J5SayaiaaCZhY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=kXjPz79n/jIk5h1I9gBltX0GNP5tHRXfcdQl7fnB7objdBiAswlKsu/FI8817UOJ3Ow0yHjIp/YoegDzERzdTfwl+DHYPnMDtLBgARcSj5FtN7LhLgTzFQCb8zAkVskPs2lfeVX9rN62VFxTIUXWMYYGoiA/9xZ7iclWese//aQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [10.2.5.213]) by gateway (Coremail) with SMTP id _____8CxrsPOtHhpMR4NAA--.43386S3; Tue, 27 Jan 2026 20:51:26 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.5.213]) by front1 (Coremail) with SMTP id qMiowJAxWcHMtHhpYpo0AA--.24006S4; Tue, 27 Jan 2026 20:51:26 +0800 (CST) From: Bibo Mao To: Huacai Chen , WANG Xuerui , Tianrui Zhao Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: [PATCH v2 2/3] LoongArch: KVM: Move LASX capability check in LASX exception handler Date: Tue, 27 Jan 2026 20:51:23 +0800 Message-Id: <20260127125124.3234252-3-maobibo@loongson.cn> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20260127125124.3234252-1-maobibo@loongson.cn> References: <20260127125124.3234252-1-maobibo@loongson.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: qMiowJAxWcHMtHhpYpo0AA--.24006S4 X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ X-Coremail-Antispam: 1Uk129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7 ZEXasCq-sGcSsGvfJ3UbIjqfuFe4nvWSU5nxnvy29KBjDU0xBIdaVrnUUvcSsGvfC2Kfnx nUUI43ZEXa7xR_UUUUUUUUU== Content-Type: text/plain; charset="utf-8" Like FPU exception handler, check LASX capability in LASX exception handler rather than function kvm_own_lasx(). LASX capability in function kvm_guest_has_lasx() implies FPU and LSX capability, only checking kvm_guest_has_lasx() is ok here. Signed-off-by: Bibo Mao --- arch/loongarch/kvm/exit.c | 4 +++- arch/loongarch/kvm/vcpu.c | 3 --- 2 files changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c index 76eec3f24953..74b427287e96 100644 --- a/arch/loongarch/kvm/exit.c +++ b/arch/loongarch/kvm/exit.c @@ -810,8 +810,10 @@ static int kvm_handle_lsx_disabled(struct kvm_vcpu *vc= pu, int ecode) */ static int kvm_handle_lasx_disabled(struct kvm_vcpu *vcpu, int ecode) { - if (kvm_own_lasx(vcpu)) + if (!kvm_guest_has_lasx(&vcpu->arch)) kvm_queue_exception(vcpu, EXCCODE_INE, 0); + else + kvm_own_lasx(vcpu); =20 return RESUME_GUEST; } diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c index aff295aa6b0b..d91a1160a309 100644 --- a/arch/loongarch/kvm/vcpu.c +++ b/arch/loongarch/kvm/vcpu.c @@ -1391,9 +1391,6 @@ int kvm_own_lsx(struct kvm_vcpu *vcpu) /* Enable LASX and restore context */ int kvm_own_lasx(struct kvm_vcpu *vcpu) { - if (!kvm_guest_has_fpu(&vcpu->arch) || !kvm_guest_has_lsx(&vcpu->arch) ||= !kvm_guest_has_lasx(&vcpu->arch)) - return -EINVAL; - preempt_disable(); =20 kvm_check_fcsr(vcpu, vcpu->arch.fpu.fcsr); --=20 2.39.3 From nobody Mon Feb 9 05:43:48 2026 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7E21E355042; Tue, 27 Jan 2026 12:51:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769518294; cv=none; b=uQMHiXl7w7K+WOZST9SzfDSh5g7k7m/OTkYFfTR+an+oBGiGfhjFFA+poR48XeiYM1v3wBMtF3R1NYPMNbtvveu9WL5Uar3f5suVyYr1xPnBqOW0lbC9H2f2bS/8uXCQVKJ2HJvT3QRkKq7KDUM3iyI6QtJim1+mXMS9rN6k1ik= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769518294; c=relaxed/simple; bh=7YIh20H2by5sDVrbfxOP83AGWSzPQwwRkf2iETQ6jlc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ieqLEIhMglzHJBbwn3JtF56sfDYbDLltUWkZTHPAEDFX/LTlFx9hH34PQer5VSVkKPfaQ6zAXjTht4Bz8NyTEumuQRnp6aqY8LZTFT0BdWr185s8iJXAzOfoV/xYCudJox0lnpQTkDwwLE0qtjm8H7M+DVMhG3D6jKD78wC7lfw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [10.2.5.213]) by gateway (Coremail) with SMTP id _____8DxAfHOtHhpNR4NAA--.43149S3; Tue, 27 Jan 2026 20:51:26 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.5.213]) by front1 (Coremail) with SMTP id qMiowJAxWcHMtHhpYpo0AA--.24006S5; Tue, 27 Jan 2026 20:51:26 +0800 (CST) From: Bibo Mao To: Huacai Chen , WANG Xuerui , Tianrui Zhao Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: [PATCH v2 3/3] LoongArch: KVM: Add FPU delay load support Date: Tue, 27 Jan 2026 20:51:24 +0800 Message-Id: <20260127125124.3234252-4-maobibo@loongson.cn> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20260127125124.3234252-1-maobibo@loongson.cn> References: <20260127125124.3234252-1-maobibo@loongson.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: qMiowJAxWcHMtHhpYpo0AA--.24006S5 X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ X-Coremail-Antispam: 1Uk129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7 ZEXasCq-sGcSsGvfJ3UbIjqfuFe4nvWSU5nxnvy29KBjDU0xBIdaVrnUUvcSsGvfC2Kfnx nUUI43ZEXa7xR_UUUUUUUUU== Content-Type: text/plain; charset="utf-8" FPU is lazy enabled with KVM hypervisor. After FPU is enabled and loaded, vCPU can be preempted and FPU will be lost again. Here FPU is delay load until guest enter entry. Signed-off-by: Bibo Mao --- arch/loongarch/include/asm/kvm_host.h | 2 ++ arch/loongarch/kvm/exit.c | 15 ++++++++---- arch/loongarch/kvm/vcpu.c | 33 +++++++++++++++++---------- 3 files changed, 33 insertions(+), 17 deletions(-) diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include= /asm/kvm_host.h index e4fe5b8e8149..902ff7bc0e35 100644 --- a/arch/loongarch/include/asm/kvm_host.h +++ b/arch/loongarch/include/asm/kvm_host.h @@ -37,6 +37,7 @@ #define KVM_REQ_TLB_FLUSH_GPA KVM_ARCH_REQ(0) #define KVM_REQ_STEAL_UPDATE KVM_ARCH_REQ(1) #define KVM_REQ_PMU KVM_ARCH_REQ(2) +#define KVM_REQ_FPU_LOAD KVM_ARCH_REQ(3) =20 #define KVM_GUESTDBG_SW_BP_MASK \ (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP) @@ -234,6 +235,7 @@ struct kvm_vcpu_arch { u64 vpid; gpa_t flush_gpa; =20 + int fpu_load_type; /* Frequency of stable timer in Hz */ u64 timer_mhz; ktime_t expire; diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c index 74b427287e96..b6f08df8fedb 100644 --- a/arch/loongarch/kvm/exit.c +++ b/arch/loongarch/kvm/exit.c @@ -754,7 +754,8 @@ static int kvm_handle_fpu_disabled(struct kvm_vcpu *vcp= u, int ecode) return RESUME_HOST; } =20 - kvm_own_fpu(vcpu); + vcpu->arch.fpu_load_type =3D KVM_LARCH_FPU; + kvm_make_request(KVM_REQ_FPU_LOAD, vcpu); =20 return RESUME_GUEST; } @@ -794,8 +795,10 @@ static int kvm_handle_lsx_disabled(struct kvm_vcpu *vc= pu, int ecode) { if (!kvm_guest_has_lsx(&vcpu->arch)) kvm_queue_exception(vcpu, EXCCODE_INE, 0); - else - kvm_own_lsx(vcpu); + else { + vcpu->arch.fpu_load_type =3D KVM_LARCH_LSX; + kvm_make_request(KVM_REQ_FPU_LOAD, vcpu); + } =20 return RESUME_GUEST; } @@ -812,8 +815,10 @@ static int kvm_handle_lasx_disabled(struct kvm_vcpu *v= cpu, int ecode) { if (!kvm_guest_has_lasx(&vcpu->arch)) kvm_queue_exception(vcpu, EXCCODE_INE, 0); - else - kvm_own_lasx(vcpu); + else { + vcpu->arch.fpu_load_type =3D KVM_LARCH_LASX; + kvm_make_request(KVM_REQ_FPU_LOAD, vcpu); + } =20 return RESUME_GUEST; } diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c index d91a1160a309..3e749e9738b2 100644 --- a/arch/loongarch/kvm/vcpu.c +++ b/arch/loongarch/kvm/vcpu.c @@ -232,6 +232,27 @@ static void kvm_late_check_requests(struct kvm_vcpu *v= cpu) kvm_flush_tlb_gpa(vcpu, vcpu->arch.flush_gpa); vcpu->arch.flush_gpa =3D INVALID_GPA; } + + if (kvm_check_request(KVM_REQ_FPU_LOAD, vcpu)) { + switch (vcpu->arch.fpu_load_type) { + case KVM_LARCH_FPU: + kvm_own_fpu(vcpu); + break; + + case KVM_LARCH_LSX: + kvm_own_lsx(vcpu); + break; + + case KVM_LARCH_LASX: + kvm_own_lasx(vcpu); + break; + + default: + break; + } + + vcpu->arch.fpu_load_type =3D 0; + } } =20 /* @@ -1338,8 +1359,6 @@ static inline void kvm_check_fcsr_alive(struct kvm_vc= pu *vcpu) { } /* Enable FPU and restore context */ void kvm_own_fpu(struct kvm_vcpu *vcpu) { - preempt_disable(); - /* * Enable FPU for guest * Set FR and FRE according to guest context @@ -1350,16 +1369,12 @@ void kvm_own_fpu(struct kvm_vcpu *vcpu) kvm_restore_fpu(&vcpu->arch.fpu); vcpu->arch.aux_inuse |=3D KVM_LARCH_FPU; trace_kvm_aux(vcpu, KVM_TRACE_AUX_RESTORE, KVM_TRACE_AUX_FPU); - - preempt_enable(); } =20 #ifdef CONFIG_CPU_HAS_LSX /* Enable LSX and restore context */ int kvm_own_lsx(struct kvm_vcpu *vcpu) { - preempt_disable(); - /* Enable LSX for guest */ kvm_check_fcsr(vcpu, vcpu->arch.fpu.fcsr); set_csr_euen(CSR_EUEN_LSXEN | CSR_EUEN_FPEN); @@ -1381,8 +1396,6 @@ int kvm_own_lsx(struct kvm_vcpu *vcpu) =20 trace_kvm_aux(vcpu, KVM_TRACE_AUX_RESTORE, KVM_TRACE_AUX_LSX); vcpu->arch.aux_inuse |=3D KVM_LARCH_LSX | KVM_LARCH_FPU; - preempt_enable(); - return 0; } #endif @@ -1391,8 +1404,6 @@ int kvm_own_lsx(struct kvm_vcpu *vcpu) /* Enable LASX and restore context */ int kvm_own_lasx(struct kvm_vcpu *vcpu) { - preempt_disable(); - kvm_check_fcsr(vcpu, vcpu->arch.fpu.fcsr); set_csr_euen(CSR_EUEN_FPEN | CSR_EUEN_LSXEN | CSR_EUEN_LASXEN); switch (vcpu->arch.aux_inuse & (KVM_LARCH_FPU | KVM_LARCH_LSX)) { @@ -1414,8 +1425,6 @@ int kvm_own_lasx(struct kvm_vcpu *vcpu) =20 trace_kvm_aux(vcpu, KVM_TRACE_AUX_RESTORE, KVM_TRACE_AUX_LASX); vcpu->arch.aux_inuse |=3D KVM_LARCH_LASX | KVM_LARCH_LSX | KVM_LARCH_FPU; - preempt_enable(); - return 0; } #endif --=20 2.39.3