From patchwork Sat Mar 2 08:25:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bibo Mao X-Patchwork-Id: 13579490 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id DD6EA18AE8; Sat, 2 Mar 2024 08:25:43 +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=1709367946; cv=none; b=uSTu3vIqGMGd+DZ9Ov9IkVUQqVh1cBqtTYRaNyQmtGiKEKgvcdD4dtl7f6r05F5fkNhQuY0wrLhl6Xv3n/eXewbVs+TNqTrpoocKRIOjRuaQEQcOEwALHAbyFrOHzG77/bjJLZEPgL4cLPPh5vT+QhKOWDyW4K0r42pQUHcnax4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709367946; c=relaxed/simple; bh=6KlCP0Y7mt6HFQhKkxD7voeovFGOnJaYnqL3+sPLoBU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=DDsoRF6e2Kk26UaMg01/yj1xjUQj/hq3t3b4+DKzUiPiJyqzBqYODGLtGrlwYccZmZF4EwCkHvyEm1pkmZbi2yaeBtQFQbYf/aiudd8oz8KguA06gggtLQ1/0CfEe+GT7JRN6Lz0cMKJl3fW4n5W02+UlH44aeMHbL2U2OSFHFQ= 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 _____8CxXOmF4uJlKooTAA--.39629S3; Sat, 02 Mar 2024 16:25:41 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.5.213]) by localhost.localdomain (Coremail) with SMTP id AQAAf8CxLBN84uJlqlhMAA--.6847S7; Sat, 02 Mar 2024 16:25:39 +0800 (CST) From: Bibo Mao To: Huacai Chen , Tianrui Zhao , Juergen Gross , Paolo Bonzini , Jonathan Corbet Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, virtualization@lists.linux.dev, kvm@vger.kernel.org Subject: [PATCH v6 5/7] LoongArch: KVM: Add pv ipi support on kvm side Date: Sat, 2 Mar 2024 16:25:30 +0800 Message-Id: <20240302082532.1415200-6-maobibo@loongson.cn> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240302082532.1415200-1-maobibo@loongson.cn> References: <20240302082532.1415200-1-maobibo@loongson.cn> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: AQAAf8CxLBN84uJlqlhMAA--.6847S7 X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ X-Coremail-Antispam: 1Uk129KBj93XoW3Gw17ZF1DJry5Kr1kZryfKrX_yoWfAw45pF y8Cwn5KFWYgrWfC347Jr9Igry5uFn3Gry2vFZIy3yrAa1jy3WrXrW8KFWDAF15J34kZ3WS qFWYqwsruFZrJ3cCm3ZEXasCq-sJn29KB7ZKAUJUUUUd529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUBqb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AK xVW8Jr0_Cr1UM2kKe7AKxVWUtVW8ZwAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07 AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWr XVW3AwAv7VC2z280aVAFwI0_Cr0_Gr1UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x 0EwIxGrwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkE bVWUJVW8JwCFI7km07C267AKxVWUtVW8ZwC20s026c02F40E14v26r1j6r18MI8I3I0E74 80Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0 I7IYx2IY67AKxVW5JVW7JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04 k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26F4j6r4UJwCI42IY6I8E87Iv6xkF 7I0E14v26r4UJVWxJrUvcSsGvfC2KfnxnUUI43ZEXa7IUnbAw7UUUUU== On LoongArch system, ipi hw uses iocsr registers, there is one iocsr register access on ipi sending, and two iocsr access on ipi receiving which is ipi interrupt handler. On VM mode all iocsr accessing will cause VM to trap into hypervisor. So with one ipi hw notification there will be three times of trap. PV ipi is added for VM, hypercall instruction is used for ipi sender, and hypervisor will inject SWI to destination vcpu. During SWI interrupt handler, only estat CSR register is written to clear irq. Estat CSR register access will not trap into hypervisor. So with pv ipi supported, there is one trap with pv ipi sender, and no trap with ipi receiver, there is only one trap with ipi notification. Also this patch adds ipi multicast support, the method is similar with x86. With ipi multicast support, ipi notification can be sent to at most 128 vcpus at one time. It reduces trap times into hypervisor greatly. Signed-off-by: Bibo Mao --- arch/loongarch/include/asm/kvm_host.h | 1 + arch/loongarch/include/asm/kvm_para.h | 130 +++++++++++++++++++++++++ arch/loongarch/include/asm/loongarch.h | 1 + arch/loongarch/kvm/exit.c | 76 ++++++++++++++- arch/loongarch/kvm/vcpu.c | 1 + 5 files changed, 207 insertions(+), 2 deletions(-) diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h index 3ba16ef1fe69..0b96c6303cf7 100644 --- a/arch/loongarch/include/asm/kvm_host.h +++ b/arch/loongarch/include/asm/kvm_host.h @@ -43,6 +43,7 @@ struct kvm_vcpu_stat { u64 idle_exits; u64 cpucfg_exits; u64 signal_exits; + u64 hypercall_exits; }; #define KVM_MEM_HUGEPAGE_CAPABLE (1UL << 0) diff --git a/arch/loongarch/include/asm/kvm_para.h b/arch/loongarch/include/asm/kvm_para.h index d48f993ae206..a82bffbbf8a1 100644 --- a/arch/loongarch/include/asm/kvm_para.h +++ b/arch/loongarch/include/asm/kvm_para.h @@ -2,6 +2,16 @@ #ifndef _ASM_LOONGARCH_KVM_PARA_H #define _ASM_LOONGARCH_KVM_PARA_H +/* + * Hypercall code field + */ +#define HYPERVISOR_KVM 1 +#define HYPERVISOR_VENDOR_SHIFT 8 +#define HYPERCALL_CODE(vendor, code) ((vendor << HYPERVISOR_VENDOR_SHIFT) + code) +#define KVM_HCALL_CODE_PV_SERVICE 0 +#define KVM_HCALL_PV_SERVICE HYPERCALL_CODE(HYPERVISOR_KVM, KVM_HCALL_CODE_PV_SERVICE) +#define KVM_HCALL_FUNC_PV_IPI 1 + /* * LoongArch hypercall return code */ @@ -9,6 +19,126 @@ #define KVM_HCALL_INVALID_CODE -1UL #define KVM_HCALL_INVALID_PARAMETER -2UL +/* + * Hypercall interface for KVM hypervisor + * + * a0: function identifier + * a1-a6: args + * Return value will be placed in v0. + * Up to 6 arguments are passed in a1, a2, a3, a4, a5, a6. + */ +static __always_inline long kvm_hypercall(u64 fid) +{ + register long ret asm("v0"); + register unsigned long fun asm("a0") = fid; + + __asm__ __volatile__( + "hvcl "__stringify(KVM_HCALL_PV_SERVICE) + : "=r" (ret) + : "r" (fun) + : "memory" + ); + + return ret; +} + +static __always_inline long kvm_hypercall1(u64 fid, unsigned long arg0) +{ + register long ret asm("v0"); + register unsigned long fun asm("a0") = fid; + register unsigned long a1 asm("a1") = arg0; + + __asm__ __volatile__( + "hvcl "__stringify(KVM_HCALL_PV_SERVICE) + : "=r" (ret) + : "r" (fun), "r" (a1) + : "memory" + ); + + return ret; +} + +static __always_inline long kvm_hypercall2(u64 fid, + unsigned long arg0, unsigned long arg1) +{ + register long ret asm("v0"); + register unsigned long fun asm("a0") = fid; + register unsigned long a1 asm("a1") = arg0; + register unsigned long a2 asm("a2") = arg1; + + __asm__ __volatile__( + "hvcl "__stringify(KVM_HCALL_PV_SERVICE) + : "=r" (ret) + : "r" (fun), "r" (a1), "r" (a2) + : "memory" + ); + + return ret; +} + +static __always_inline long kvm_hypercall3(u64 fid, + unsigned long arg0, unsigned long arg1, unsigned long arg2) +{ + register long ret asm("v0"); + register unsigned long fun asm("a0") = fid; + register unsigned long a1 asm("a1") = arg0; + register unsigned long a2 asm("a2") = arg1; + register unsigned long a3 asm("a3") = arg2; + + __asm__ __volatile__( + "hvcl "__stringify(KVM_HCALL_PV_SERVICE) + : "=r" (ret) + : "r" (fun), "r" (a1), "r" (a2), "r" (a3) + : "memory" + ); + + return ret; +} + +static __always_inline long kvm_hypercall4(u64 fid, + unsigned long arg0, unsigned long arg1, unsigned long arg2, + unsigned long arg3) +{ + register long ret asm("v0"); + register unsigned long fun asm("a0") = fid; + register unsigned long a1 asm("a1") = arg0; + register unsigned long a2 asm("a2") = arg1; + register unsigned long a3 asm("a3") = arg2; + register unsigned long a4 asm("a4") = arg3; + + __asm__ __volatile__( + "hvcl "__stringify(KVM_HCALL_PV_SERVICE) + : "=r" (ret) + : "r"(fun), "r" (a1), "r" (a2), "r" (a3), "r" (a4) + : "memory" + ); + + return ret; +} + +static __always_inline long kvm_hypercall5(u64 fid, + unsigned long arg0, unsigned long arg1, unsigned long arg2, + unsigned long arg3, unsigned long arg4) +{ + register long ret asm("v0"); + register unsigned long fun asm("a0") = fid; + register unsigned long a1 asm("a1") = arg0; + register unsigned long a2 asm("a2") = arg1; + register unsigned long a3 asm("a3") = arg2; + register unsigned long a4 asm("a4") = arg3; + register unsigned long a5 asm("a5") = arg4; + + __asm__ __volatile__( + "hvcl "__stringify(KVM_HCALL_PV_SERVICE) + : "=r" (ret) + : "r"(fun), "r" (a1), "r" (a2), "r" (a3), "r" (a4), "r" (a5) + : "memory" + ); + + return ret; +} + + static inline unsigned int kvm_arch_para_features(void) { return 0; diff --git a/arch/loongarch/include/asm/loongarch.h b/arch/loongarch/include/asm/loongarch.h index a1d22e8b6f94..0ad36704cb4b 100644 --- a/arch/loongarch/include/asm/loongarch.h +++ b/arch/loongarch/include/asm/loongarch.h @@ -167,6 +167,7 @@ #define CPUCFG_KVM_SIG CPUCFG_KVM_BASE #define KVM_SIGNATURE "KVM\0" #define CPUCFG_KVM_FEATURE (CPUCFG_KVM_BASE + 4) +#define KVM_FEATURE_PV_IPI BIT(1) #ifndef __ASSEMBLY__ diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c index a8d3b652d3ea..933879ad0ddc 100644 --- a/arch/loongarch/kvm/exit.c +++ b/arch/loongarch/kvm/exit.c @@ -239,6 +239,12 @@ static int kvm_emu_cpucfg(struct kvm_vcpu *vcpu, larch_inst inst) else vcpu->arch.gprs[rd] = 0; break; + case CPUCFG_KVM_FEATURE: + if ((plv & CSR_CRMD_PLV) == PLV_KERN) + vcpu->arch.gprs[rd] = KVM_FEATURE_PV_IPI; + else + vcpu->arch.gprs[rd] = 0; + break; default: vcpu->arch.gprs[rd] = 0; break; @@ -712,12 +718,78 @@ static int kvm_handle_lasx_disabled(struct kvm_vcpu *vcpu) return RESUME_GUEST; } +static int kvm_pv_send_ipi(struct kvm_vcpu *vcpu) +{ + unsigned long ipi_bitmap; + unsigned int min, cpu, i; + struct kvm_vcpu *dest; + + min = vcpu->arch.gprs[LOONGARCH_GPR_A3]; + for (i = 0; i < 2; i++, min += BITS_PER_LONG) { + ipi_bitmap = vcpu->arch.gprs[LOONGARCH_GPR_A1 + i]; + if (!ipi_bitmap) + continue; + + cpu = find_first_bit((void *)&ipi_bitmap, BITS_PER_LONG); + while (cpu < BITS_PER_LONG) { + dest = kvm_get_vcpu_by_cpuid(vcpu->kvm, cpu + min); + cpu = find_next_bit((void *)&ipi_bitmap, BITS_PER_LONG, + cpu + 1); + if (!dest) + continue; + + /* + * Send SWI0 to dest vcpu to emulate IPI interrupt + */ + kvm_queue_irq(dest, INT_SWI0); + kvm_vcpu_kick(dest); + } + } + + return 0; +} + +/* + * hypercall emulation always return to guest, Caller should check retval. + */ +static void kvm_handle_pv_service(struct kvm_vcpu *vcpu) +{ + unsigned long func = vcpu->arch.gprs[LOONGARCH_GPR_A0]; + long ret; + + switch (func) { + case KVM_HCALL_FUNC_PV_IPI: + kvm_pv_send_ipi(vcpu); + ret = KVM_HCALL_STATUS_SUCCESS; + break; + default: + ret = KVM_HCALL_INVALID_CODE; + break; + }; + + vcpu->arch.gprs[LOONGARCH_GPR_A0] = ret; +} + static int kvm_handle_hypercall(struct kvm_vcpu *vcpu) { + larch_inst inst; + unsigned int code; + + inst.word = vcpu->arch.badi; + code = inst.reg0i15_format.immediate; update_pc(&vcpu->arch); - /* Treat it as noop intruction, only set return value */ - vcpu->arch.gprs[LOONGARCH_GPR_A0] = KVM_HCALL_INVALID_CODE; + switch (code) { + case KVM_HCALL_PV_SERVICE: + vcpu->stat.hypercall_exits++; + kvm_handle_pv_service(vcpu); + break; + default: + /* Treat it as noop intruction, only set return value */ + vcpu->arch.gprs[LOONGARCH_GPR_A0] = KVM_HCALL_INVALID_CODE; + break; + } + return RESUME_GUEST; } diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c index a1a1dc4a3cf2..5a4b0db9c36f 100644 --- a/arch/loongarch/kvm/vcpu.c +++ b/arch/loongarch/kvm/vcpu.c @@ -19,6 +19,7 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = { STATS_DESC_COUNTER(VCPU, idle_exits), STATS_DESC_COUNTER(VCPU, cpucfg_exits), STATS_DESC_COUNTER(VCPU, signal_exits), + STATS_DESC_COUNTER(VCPU, hypercall_exits) }; const struct kvm_stats_header kvm_vcpu_stats_header = {