From patchwork Fri Jul 19 16:09:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anup Patel X-Patchwork-Id: 13737410 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4FA60C3DA5D for ; Fri, 19 Jul 2024 16:10:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=hJZuhdSzQST7iYYM9AsT4qrZbAApf3Fud6yG56bRKuM=; b=2YExvwudroJvTJ ThDJgNMp66n/RQq7FubIdcvgakJSXgSWqxyxWHzUBNhui+PduOsUp89igSyK1BIkhy+LQL5Zw0vIN 0MYTAHkPZf/LJJqSKC1zzfzGhC/y6HJsIqT4aFwkuk0G/uC7fHmJGgTtewxavE/q3GruyfNcvEegw v19nNafy7JIY/GFomraOHo/hqM0EgusVVaJdtkpbAQugY5bnWC5Gu8bch4Kmy9E+8/UC616MKLXiJ MdgsFXV8dTo4lfVJmyZJJRSotKU7XHFqegQJ+4+hzWX/BBcIyS1IzQSGX227HwFmJc5TsYRAzo+Sf EfMr5XbUiDwF/1NP7i/w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sUqBJ-00000003Baz-2frh; Fri, 19 Jul 2024 16:10:05 +0000 Received: from mail-pl1-x636.google.com ([2607:f8b0:4864:20::636]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sUqB7-00000003BQB-2bEG for linux-riscv@lists.infradead.org; Fri, 19 Jul 2024 16:09:59 +0000 Received: by mail-pl1-x636.google.com with SMTP id d9443c01a7336-1fb3b7d0d3aso12773935ad.2 for ; Fri, 19 Jul 2024 09:09:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ventanamicro.com; s=google; t=1721405393; x=1722010193; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=pNRjpl9AWOu5Y/06ZXovZLxYd73eZ2CcfqE7LV9a3jU=; b=gUxEjbP8BpXgGukOF/suXynrE076z7yLh2xnLc85GkoDICrlcLqHL+bfnLQPyOL3wP 8w8we7x4+5Qt4SA8KWieuyxQbQpXMnqpjR+7w2+RE7kGhUvkdlLfT06D09CEMCTuHSlD gT/qG7UUIVxApWrHiGbN5QIhcP4GejEkZ9fOxreRDEJ3fAB8f1DS+HOZquTJ6ch5d5kk jo5uXlC6fpTonvKnBPANd/1/eqH3D9NaUDTdhhYY179HY9lNi/w8FclMyiE15Nk9MR6S A5NJiH5G/EmjxuBCztd91W/uv/yFfdUYdGULm5uCTNnWUgRLdIjjznubTz0s/7C/6XGs vVtg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721405393; x=1722010193; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=pNRjpl9AWOu5Y/06ZXovZLxYd73eZ2CcfqE7LV9a3jU=; b=chF9hEGnfEuPQjxTzQro/OWVGiqJGf4XLB0yxL5lO99Ul27LfDTe3+0n0KtdWhslEY B9FbD/0ows613ODtDEoK6uHmwD2BtvKRwi2ompDLQYSGSIe7oaMoqvSS+8hsUykis+tO 1SaIDA400srm0/feQsHRn7UH+a1ur7kVGTPNuWA18BbP18k9cth0axsyrGnekue9puSY ZvS4QVcKh6egn008UwUBjrKLy/QW71SGrVR7wWXdigDjo5+EDg+XTyRj4WDwIvIbBGkc JX6jDW6VSBMod0wmCK24cWsplg56Ltf/L3BB2T4GiifaYQaEuQ/DB2q2Hf+PJPiEI0e3 geJQ== X-Forwarded-Encrypted: i=1; AJvYcCVlI2jfsvgL8by30VWH6tUA+yCxx+W4QvH2144ut997uGYv17YzxcaCZTU0km97E9u7lGGPGL+hCJtPu8nvGtzdEawPABins7CLfnZK9MyF X-Gm-Message-State: AOJu0YyCUlzOClJCbAv2UN1TTgeneeZa71JMJ67sU9N3nS+k4OD0hpo/ A7hJE3Mki0zE1HAPqe7ZVdQQuPQnxZZiwr+LWv9TGsYA5MzpbqmlJXwA1g2Z0n8= X-Google-Smtp-Source: AGHT+IGsSBffRZbxlhKIbUi3MquECwG/00bsx5PoG3YEzYyosi1BS/71TDciBJgkl9GHm7KPMmnNHw== X-Received: by 2002:a17:902:e547:b0:1fa:ab25:f625 with SMTP id d9443c01a7336-1fd74585690mr3006245ad.38.1721405392800; Fri, 19 Jul 2024 09:09:52 -0700 (PDT) Received: from anup-ubuntu-vm.localdomain ([223.185.135.236]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1fd6f28f518sm6632615ad.69.2024.07.19.09.09.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Jul 2024 09:09:52 -0700 (PDT) From: Anup Patel To: Palmer Dabbelt , Paul Walmsley Cc: Atish Patra , Andrew Jones , Anup Patel , kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Anup Patel Subject: [PATCH 08/13] RISC-V: KVM: Add common nested acceleration support Date: Fri, 19 Jul 2024 21:39:08 +0530 Message-Id: <20240719160913.342027-9-apatel@ventanamicro.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240719160913.342027-1-apatel@ventanamicro.com> References: <20240719160913.342027-1-apatel@ventanamicro.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240719_090953_724834_E362B466 X-CRM114-Status: GOOD ( 24.29 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Add a common nested acceleration support which will be shared by all parts of KVM RISC-V. This nested acceleration support detects and enables SBI NACL extension usage based on static keys which ensures minimum impact on the non-nested scenario. Signed-off-by: Anup Patel Reviewed-by: Atish Patra --- arch/riscv/include/asm/kvm_nacl.h | 205 ++++++++++++++++++++++++++++++ arch/riscv/kvm/Makefile | 1 + arch/riscv/kvm/main.c | 53 +++++++- arch/riscv/kvm/nacl.c | 152 ++++++++++++++++++++++ 4 files changed, 409 insertions(+), 2 deletions(-) create mode 100644 arch/riscv/include/asm/kvm_nacl.h create mode 100644 arch/riscv/kvm/nacl.c diff --git a/arch/riscv/include/asm/kvm_nacl.h b/arch/riscv/include/asm/kvm_nacl.h new file mode 100644 index 000000000000..a704e8000a58 --- /dev/null +++ b/arch/riscv/include/asm/kvm_nacl.h @@ -0,0 +1,205 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2024 Ventana Micro Systems Inc. + */ + +#ifndef __KVM_NACL_H +#define __KVM_NACL_H + +#include +#include +#include +#include +#include + +DECLARE_STATIC_KEY_FALSE(kvm_riscv_nacl_available); +#define kvm_riscv_nacl_available() \ + static_branch_unlikely(&kvm_riscv_nacl_available) + +DECLARE_STATIC_KEY_FALSE(kvm_riscv_nacl_sync_csr_available); +#define kvm_riscv_nacl_sync_csr_available() \ + static_branch_unlikely(&kvm_riscv_nacl_sync_csr_available) + +DECLARE_STATIC_KEY_FALSE(kvm_riscv_nacl_sync_hfence_available); +#define kvm_riscv_nacl_sync_hfence_available() \ + static_branch_unlikely(&kvm_riscv_nacl_sync_hfence_available) + +DECLARE_STATIC_KEY_FALSE(kvm_riscv_nacl_sync_sret_available); +#define kvm_riscv_nacl_sync_sret_available() \ + static_branch_unlikely(&kvm_riscv_nacl_sync_sret_available) + +DECLARE_STATIC_KEY_FALSE(kvm_riscv_nacl_autoswap_csr_available); +#define kvm_riscv_nacl_autoswap_csr_available() \ + static_branch_unlikely(&kvm_riscv_nacl_autoswap_csr_available) + +struct kvm_riscv_nacl { + void *shmem; + phys_addr_t shmem_phys; +}; +DECLARE_PER_CPU(struct kvm_riscv_nacl, kvm_riscv_nacl); + +void __kvm_riscv_nacl_hfence(void *shmem, + unsigned long control, + unsigned long page_num, + unsigned long page_count); + +int kvm_riscv_nacl_enable(void); + +void kvm_riscv_nacl_disable(void); + +void kvm_riscv_nacl_exit(void); + +int kvm_riscv_nacl_init(void); + +#ifdef CONFIG_32BIT +#define lelong_to_cpu(__x) le32_to_cpu(__x) +#define cpu_to_lelong(__x) cpu_to_le32(__x) +#else +#define lelong_to_cpu(__x) le64_to_cpu(__x) +#define cpu_to_lelong(__x) cpu_to_le64(__x) +#endif + +#define nacl_shmem() \ + this_cpu_ptr(&kvm_riscv_nacl)->shmem +#define nacl_shmem_fast() \ + (kvm_riscv_nacl_available() ? nacl_shmem() : NULL) + +#define nacl_sync_hfence(__e) \ + sbi_ecall(SBI_EXT_NACL, SBI_EXT_NACL_SYNC_HFENCE, \ + (__e), 0, 0, 0, 0, 0) + +#define nacl_hfence_mkconfig(__type, __order, __vmid, __asid) \ +({ \ + unsigned long __c = SBI_NACL_SHMEM_HFENCE_CONFIG_PEND; \ + __c |= ((__type) & SBI_NACL_SHMEM_HFENCE_CONFIG_TYPE_MASK) \ + << SBI_NACL_SHMEM_HFENCE_CONFIG_TYPE_SHIFT; \ + __c |= (((__order) - SBI_NACL_SHMEM_HFENCE_ORDER_BASE) & \ + SBI_NACL_SHMEM_HFENCE_CONFIG_ORDER_MASK) \ + << SBI_NACL_SHMEM_HFENCE_CONFIG_ORDER_SHIFT; \ + __c |= ((__vmid) & SBI_NACL_SHMEM_HFENCE_CONFIG_VMID_MASK) \ + << SBI_NACL_SHMEM_HFENCE_CONFIG_VMID_SHIFT; \ + __c |= ((__asid) & SBI_NACL_SHMEM_HFENCE_CONFIG_ASID_MASK); \ + __c; \ +}) + +#define nacl_hfence_mkpnum(__order, __addr) \ + ((__addr) >> (__order)) + +#define nacl_hfence_mkpcount(__order, __size) \ + ((__size) >> (__order)) + +#define nacl_hfence_gvma(__shmem, __gpa, __gpsz, __order) \ +__kvm_riscv_nacl_hfence(__shmem, \ + nacl_hfence_mkconfig(SBI_NACL_SHMEM_HFENCE_TYPE_GVMA, \ + __order, 0, 0), \ + nacl_hfence_mkpnum(__order, __gpa), \ + nacl_hfence_mkpcount(__order, __gpsz)) + +#define nacl_hfence_gvma_all(__shmem) \ +__kvm_riscv_nacl_hfence(__shmem, \ + nacl_hfence_mkconfig(SBI_NACL_SHMEM_HFENCE_TYPE_GVMA_ALL, \ + 0, 0, 0), 0, 0) + +#define nacl_hfence_gvma_vmid(__shmem, __vmid, __gpa, __gpsz, __order) \ +__kvm_riscv_nacl_hfence(__shmem, \ + nacl_hfence_mkconfig(SBI_NACL_SHMEM_HFENCE_TYPE_GVMA_VMID, \ + __order, __vmid, 0), \ + nacl_hfence_mkpnum(__order, __gpa), \ + nacl_hfence_mkpcount(__order, __gpsz)) + +#define nacl_hfence_gvma_vmid_all(__shmem, __vmid) \ +__kvm_riscv_nacl_hfence(__shmem, \ + nacl_hfence_mkconfig(SBI_NACL_SHMEM_HFENCE_TYPE_GVMA_VMID_ALL, \ + 0, __vmid, 0), 0, 0) + +#define nacl_hfence_vvma(__shmem, __vmid, __gva, __gvsz, __order) \ +__kvm_riscv_nacl_hfence(__shmem, \ + nacl_hfence_mkconfig(SBI_NACL_SHMEM_HFENCE_TYPE_VVMA, \ + __order, __vmid, 0), \ + nacl_hfence_mkpnum(__order, __gva), \ + nacl_hfence_mkpcount(__order, __gvsz)) + +#define nacl_hfence_vvma_all(__shmem, __vmid) \ +__kvm_riscv_nacl_hfence(__shmem, \ + nacl_hfence_mkconfig(SBI_NACL_SHMEM_HFENCE_TYPE_VVMA_ALL, \ + 0, __vmid, 0), 0, 0) + +#define nacl_hfence_vvma_asid(__shmem, __vmid, __asid, __gva, __gvsz, __order)\ +__kvm_riscv_nacl_hfence(__shmem, \ + nacl_hfence_mkconfig(SBI_NACL_SHMEM_HFENCE_TYPE_VVMA_ASID, \ + __order, __vmid, __asid), \ + nacl_hfence_mkpnum(__order, __gva), \ + nacl_hfence_mkpcount(__order, __gvsz)) + +#define nacl_hfence_vvma_asid_all(__shmem, __vmid, __asid) \ +__kvm_riscv_nacl_hfence(__shmem, \ + nacl_hfence_mkconfig(SBI_NACL_SHMEM_HFENCE_TYPE_VVMA_ASID_ALL, \ + 0, __vmid, __asid), 0, 0) + +#define nacl_csr_read(__shmem, __csr) \ +({ \ + unsigned long *__a = (__shmem) + SBI_NACL_SHMEM_CSR_OFFSET; \ + lelong_to_cpu(__a[SBI_NACL_SHMEM_CSR_INDEX(__csr)]); \ +}) + +#define nacl_csr_write(__shmem, __csr, __val) \ +do { \ + void *__s = (__shmem); \ + unsigned int __i = SBI_NACL_SHMEM_CSR_INDEX(__csr); \ + unsigned long *__a = (__s) + SBI_NACL_SHMEM_CSR_OFFSET; \ + u8 *__b = (__s) + SBI_NACL_SHMEM_DBITMAP_OFFSET; \ + __a[__i] = cpu_to_lelong(__val); \ + __b[__i >> 3] |= 1U << (__i & 0x7); \ +} while (0) + +#define nacl_csr_swap(__shmem, __csr, __val) \ +({ \ + void *__s = (__shmem); \ + unsigned int __i = SBI_NACL_SHMEM_CSR_INDEX(__csr); \ + unsigned long *__a = (__s) + SBI_NACL_SHMEM_CSR_OFFSET; \ + u8 *__b = (__s) + SBI_NACL_SHMEM_DBITMAP_OFFSET; \ + unsigned long __r = lelong_to_cpu(__a[__i]); \ + __a[__i] = cpu_to_lelong(__val); \ + __b[__i >> 3] |= 1U << (__i & 0x7); \ + __r; \ +}) + +#define nacl_sync_csr(__csr) \ + sbi_ecall(SBI_EXT_NACL, SBI_EXT_NACL_SYNC_CSR, \ + (__csr), 0, 0, 0, 0, 0) + +#define ncsr_read(__csr) \ +({ \ + unsigned long __r; \ + if (kvm_riscv_nacl_available()) \ + __r = nacl_csr_read(nacl_shmem(), __csr); \ + else \ + __r = csr_read(__csr); \ + __r; \ +}) + +#define ncsr_write(__csr, __val) \ +do { \ + if (kvm_riscv_nacl_sync_csr_available()) \ + nacl_csr_write(nacl_shmem(), __csr, __val); \ + else \ + csr_write(__csr, __val); \ +} while (0) + +#define ncsr_swap(__csr, __val) \ +({ \ + unsigned long __r; \ + if (kvm_riscv_nacl_sync_csr_available()) \ + __r = nacl_csr_swap(nacl_shmem(), __csr, __val); \ + else \ + __r = csr_swap(__csr, __val); \ + __r; \ +}) + +#define nsync_csr(__csr) \ +do { \ + if (kvm_riscv_nacl_sync_csr_available()) \ + nacl_sync_csr(__csr); \ +} while (0) + +#endif diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile index c1eac0d093de..0fb1840c3e0a 100644 --- a/arch/riscv/kvm/Makefile +++ b/arch/riscv/kvm/Makefile @@ -16,6 +16,7 @@ kvm-y += aia_device.o kvm-y += aia_imsic.o kvm-y += main.o kvm-y += mmu.o +kvm-y += nacl.o kvm-y += tlb.o kvm-y += vcpu.o kvm-y += vcpu_exit.o diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c index bab2ec34cd87..fd78f40bbb04 100644 --- a/arch/riscv/kvm/main.c +++ b/arch/riscv/kvm/main.c @@ -10,8 +10,8 @@ #include #include #include -#include #include +#include #include long kvm_arch_dev_ioctl(struct file *filp, @@ -22,6 +22,12 @@ long kvm_arch_dev_ioctl(struct file *filp, int kvm_arch_hardware_enable(void) { + int rc; + + rc = kvm_riscv_nacl_enable(); + if (rc) + return rc; + csr_write(CSR_HEDELEG, KVM_HEDELEG_DEFAULT); csr_write(CSR_HIDELEG, KVM_HIDELEG_DEFAULT); @@ -49,11 +55,14 @@ void kvm_arch_hardware_disable(void) csr_write(CSR_HVIP, 0); csr_write(CSR_HEDELEG, 0); csr_write(CSR_HIDELEG, 0); + + kvm_riscv_nacl_disable(); } static int __init riscv_kvm_init(void) { int rc; + char slist[64]; const char *str; if (!riscv_isa_extension_available(NULL, h)) { @@ -71,16 +80,53 @@ static int __init riscv_kvm_init(void) return -ENODEV; } + rc = kvm_riscv_nacl_init(); + if (rc && rc != -ENODEV) + return rc; + kvm_riscv_gstage_mode_detect(); kvm_riscv_gstage_vmid_detect(); rc = kvm_riscv_aia_init(); - if (rc && rc != -ENODEV) + if (rc && rc != -ENODEV) { + kvm_riscv_nacl_exit(); return rc; + } kvm_info("hypervisor extension available\n"); + if (kvm_riscv_nacl_available()) { + rc = 0; + slist[0] = '\0'; + if (kvm_riscv_nacl_sync_csr_available()) { + if (rc) + strcat(slist, ", "); + strcat(slist, "sync_csr"); + rc++; + } + if (kvm_riscv_nacl_sync_hfence_available()) { + if (rc) + strcat(slist, ", "); + strcat(slist, "sync_hfence"); + rc++; + } + if (kvm_riscv_nacl_sync_sret_available()) { + if (rc) + strcat(slist, ", "); + strcat(slist, "sync_sret"); + rc++; + } + if (kvm_riscv_nacl_autoswap_csr_available()) { + if (rc) + strcat(slist, ", "); + strcat(slist, "autoswap_csr"); + rc++; + } + kvm_info("using SBI nested acceleration with %s\n", + (rc) ? slist : "no features"); + } + switch (kvm_riscv_gstage_mode()) { case HGATP_MODE_SV32X4: str = "Sv32x4"; @@ -108,6 +154,7 @@ static int __init riscv_kvm_init(void) rc = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE); if (rc) { kvm_riscv_aia_exit(); + kvm_riscv_nacl_exit(); return rc; } @@ -119,6 +166,8 @@ static void __exit riscv_kvm_exit(void) { kvm_riscv_aia_exit(); + kvm_riscv_nacl_exit(); + kvm_exit(); } module_exit(riscv_kvm_exit); diff --git a/arch/riscv/kvm/nacl.c b/arch/riscv/kvm/nacl.c new file mode 100644 index 000000000000..08a95ad9ada2 --- /dev/null +++ b/arch/riscv/kvm/nacl.c @@ -0,0 +1,152 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2024 Ventana Micro Systems Inc. + */ + +#include +#include +#include + +DEFINE_STATIC_KEY_FALSE(kvm_riscv_nacl_available); +DEFINE_STATIC_KEY_FALSE(kvm_riscv_nacl_sync_csr_available); +DEFINE_STATIC_KEY_FALSE(kvm_riscv_nacl_sync_hfence_available); +DEFINE_STATIC_KEY_FALSE(kvm_riscv_nacl_sync_sret_available); +DEFINE_STATIC_KEY_FALSE(kvm_riscv_nacl_autoswap_csr_available); +DEFINE_PER_CPU(struct kvm_riscv_nacl, kvm_riscv_nacl); + +void __kvm_riscv_nacl_hfence(void *shmem, + unsigned long control, + unsigned long page_num, + unsigned long page_count) +{ + int i, ent = -1, try_count = 5; + unsigned long *entp; + +again: + for (i = 0; i < SBI_NACL_SHMEM_HFENCE_ENTRY_MAX; i++) { + entp = shmem + SBI_NACL_SHMEM_HFENCE_ENTRY_CONFIG(i); + if (lelong_to_cpu(*entp) & SBI_NACL_SHMEM_HFENCE_CONFIG_PEND) + continue; + + ent = i; + break; + } + + if (ent < 0) { + if (try_count) { + nacl_sync_hfence(-1UL); + goto again; + } else { + pr_warn("KVM: No free entry in NACL shared memory\n"); + return; + } + } + + entp = shmem + SBI_NACL_SHMEM_HFENCE_ENTRY_CONFIG(i); + *entp = cpu_to_lelong(control); + entp = shmem + SBI_NACL_SHMEM_HFENCE_ENTRY_PNUM(i); + *entp = cpu_to_lelong(page_num); + entp = shmem + SBI_NACL_SHMEM_HFENCE_ENTRY_PCOUNT(i); + *entp = cpu_to_lelong(page_count); +} + +int kvm_riscv_nacl_enable(void) +{ + int rc; + struct sbiret ret; + struct kvm_riscv_nacl *nacl; + + if (!kvm_riscv_nacl_available()) + return 0; + nacl = this_cpu_ptr(&kvm_riscv_nacl); + + ret = sbi_ecall(SBI_EXT_NACL, SBI_EXT_NACL_SET_SHMEM, + nacl->shmem_phys, 0, 0, 0, 0, 0); + rc = sbi_err_map_linux_errno(ret.error); + if (rc) + return rc; + + return 0; +} + +void kvm_riscv_nacl_disable(void) +{ + if (!kvm_riscv_nacl_available()) + return; + + sbi_ecall(SBI_EXT_NACL, SBI_EXT_NACL_SET_SHMEM, + SBI_SHMEM_DISABLE, SBI_SHMEM_DISABLE, 0, 0, 0, 0); +} + +void kvm_riscv_nacl_exit(void) +{ + int cpu; + struct kvm_riscv_nacl *nacl; + + if (!kvm_riscv_nacl_available()) + return; + + /* Allocate per-CPU shared memory */ + for_each_possible_cpu(cpu) { + nacl = per_cpu_ptr(&kvm_riscv_nacl, cpu); + if (!nacl->shmem) + continue; + + free_pages((unsigned long)nacl->shmem, + get_order(SBI_NACL_SHMEM_SIZE)); + nacl->shmem = NULL; + nacl->shmem_phys = 0; + } +} + +static long nacl_probe_feature(long feature_id) +{ + struct sbiret ret; + + if (!kvm_riscv_nacl_available()) + return 0; + + ret = sbi_ecall(SBI_EXT_NACL, SBI_EXT_NACL_PROBE_FEATURE, + feature_id, 0, 0, 0, 0, 0); + return ret.value; +} + +int kvm_riscv_nacl_init(void) +{ + int cpu; + struct page *shmem_page; + struct kvm_riscv_nacl *nacl; + + if (sbi_spec_version < sbi_mk_version(1, 0) || + sbi_probe_extension(SBI_EXT_NACL) <= 0) + return -ENODEV; + + /* Enable NACL support */ + static_branch_enable(&kvm_riscv_nacl_available); + + /* Probe NACL features */ + if (nacl_probe_feature(SBI_NACL_FEAT_SYNC_CSR)) + static_branch_enable(&kvm_riscv_nacl_sync_csr_available); + if (nacl_probe_feature(SBI_NACL_FEAT_SYNC_HFENCE)) + static_branch_enable(&kvm_riscv_nacl_sync_hfence_available); + if (nacl_probe_feature(SBI_NACL_FEAT_SYNC_SRET)) + static_branch_enable(&kvm_riscv_nacl_sync_sret_available); + if (nacl_probe_feature(SBI_NACL_FEAT_AUTOSWAP_CSR)) + static_branch_enable(&kvm_riscv_nacl_autoswap_csr_available); + + /* Allocate per-CPU shared memory */ + for_each_possible_cpu(cpu) { + nacl = per_cpu_ptr(&kvm_riscv_nacl, cpu); + + shmem_page = alloc_pages(GFP_KERNEL | __GFP_ZERO, + get_order(SBI_NACL_SHMEM_SIZE)); + if (!shmem_page) { + kvm_riscv_nacl_exit(); + return -ENOMEM; + } + nacl->shmem = page_to_virt(shmem_page); + nacl->shmem_phys = page_to_phys(shmem_page); + } + + return 0; +}