From mboxrd@z Thu Jan 1 00:00:00 1970 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 CA79410D14AC for ; Mon, 30 Mar 2026 12:26:54 +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=UiU+qR2eFust29k/23YLTnGxTEvgkim8LrvJsNEueb0=; b=MN6BlZoFw63ldM /L5X4jLMtHLITDRngqk8r6AhqOjIcQRAtXGfJYyeoHi6sYkHEathDsrKHTFzZjCG0u/tBX+IRqevI V5xDE690UyET9EmYbdIK0hUdncNGBhAIV2n43LXA3VQo3pIRbRF75DMHkx+3+n5Ye4aY4cc/0RXZx SmJnkydQOvF02VAlIit8adVF5ywwjZxWS58dnWc3fwjahyc3WvsRS9afBZIq8NpFYemhiCF4qwqyZ U3f8bLoFflj7sWjV6V78UHWnbBr6+b/ruqnemRtw7rHaJU0CmqQoDOAff3ag2dLbXjO/bKfekEyEE Bk9dGWsVWtQj63MOU4pg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w7Bhg-0000000BFpi-0voU; Mon, 30 Mar 2026 12:26:48 +0000 Received: from out30-113.freemail.mail.aliyun.com ([115.124.30.113]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w7BhZ-0000000BFjk-2qtz; Mon, 30 Mar 2026 12:26:43 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1774873594; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=PT+yx01BbG86omMromavfHwf6ELYE5YcV+gpW/gZMbk=; b=bi2nMf/1BxcM313nB4MzRBmi2Sfl9uCZX8SyppCIWHvT+qS0R7P2BLKi6OcnH3WIda3ZFX3LeyqxVtk8Y5aP5A6MLbQt2VDy6+4ch79h9oiSFXGWqNIdSY9qDz/860/Ac67FChyurIGmGFVqLQV37lOJ6swx2UHysZ0XhE0m9ok= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam011083073210;MF=fangyu.yu@linux.alibaba.com;NM=1;PH=DS;RN=18;SR=0;TI=SMTPD_---0X.zfcJ9_1774873591; Received: from localhost.localdomain(mailfrom:fangyu.yu@linux.alibaba.com fp:SMTPD_---0X.zfcJ9_1774873591 cluster:ay36) by smtp.aliyun-inc.com; Mon, 30 Mar 2026 20:26:32 +0800 From: fangyu.yu@linux.alibaba.com To: pbonzini@redhat.com, corbet@lwn.net, anup@brainfault.org, atish.patra@linux.dev, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, skhan@linuxfoundation.org Cc: guoren@kernel.org, radim.krcmar@oss.qualcomm.com, andrew.jones@oss.qualcomm.com, linux-doc@vger.kernel.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Fangyu Yu Subject: [PATCH v6 3/4] RISC-V: KVM: Detect and expose supported HGATP G-stage modes Date: Mon, 30 Mar 2026 20:26:00 +0800 Message-Id: <20260330122601.22140-4-fangyu.yu@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20260330122601.22140-1-fangyu.yu@linux.alibaba.com> References: <20260330122601.22140-1-fangyu.yu@linux.alibaba.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260330_052641_909954_30460013 X-CRM114-Status: GOOD ( 10.38 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Fangyu Yu Extend kvm_riscv_gstage_mode_detect() to probe all HGATP.MODE values supported by the host and record them in a bitmask. Keep tracking the maximum supported G-stage page table level for existing internal users. Also provide lightweight helpers to retrieve the supported-mode bitmask and validate a requested HGATP.MODE against it. Signed-off-by: Fangyu Yu Reviewed-by: Andrew Jones --- arch/riscv/include/asm/kvm_gstage.h | 11 ++++++++ arch/riscv/kvm/gstage.c | 43 +++++++++++++++-------------- 2 files changed, 34 insertions(+), 20 deletions(-) diff --git a/arch/riscv/include/asm/kvm_gstage.h b/arch/riscv/include/asm/kvm_gstage.h index 70d9d483365e..bbf8f45c6563 100644 --- a/arch/riscv/include/asm/kvm_gstage.h +++ b/arch/riscv/include/asm/kvm_gstage.h @@ -31,6 +31,7 @@ struct kvm_gstage_mapping { #endif extern unsigned long kvm_riscv_gstage_max_pgd_levels; +extern u32 kvm_riscv_gstage_supported_mode_mask; #define kvm_riscv_gstage_pgd_xbits 2 #define kvm_riscv_gstage_pgd_size (1UL << (HGATP_PAGE_SHIFT + kvm_riscv_gstage_pgd_xbits)) @@ -102,4 +103,14 @@ static inline void kvm_riscv_gstage_init(struct kvm_gstage *gstage, struct kvm * gstage->pgd_levels = kvm->arch.pgd_levels; } +static inline u32 kvm_riscv_get_hgatp_mode_mask(void) +{ + return kvm_riscv_gstage_supported_mode_mask; +} + +static inline bool kvm_riscv_hgatp_mode_is_valid(unsigned long mode) +{ + return kvm_riscv_gstage_supported_mode_mask & BIT(mode); +} + #endif diff --git a/arch/riscv/kvm/gstage.c b/arch/riscv/kvm/gstage.c index 7c4c34bc191b..459041255c14 100644 --- a/arch/riscv/kvm/gstage.c +++ b/arch/riscv/kvm/gstage.c @@ -16,6 +16,8 @@ unsigned long kvm_riscv_gstage_max_pgd_levels __ro_after_init = 3; #else unsigned long kvm_riscv_gstage_max_pgd_levels __ro_after_init = 2; #endif +/* Bitmask of supported HGATP.MODE encodings (BIT(HGATP_MODE_*)). */ +u32 kvm_riscv_gstage_supported_mode_mask __ro_after_init; #define gstage_pte_leaf(__ptep) \ (pte_val(*(__ptep)) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)) @@ -315,42 +317,43 @@ void kvm_riscv_gstage_wp_range(struct kvm_gstage *gstage, gpa_t start, gpa_t end } } +static bool __init kvm_riscv_hgatp_mode_supported(unsigned long mode) +{ + csr_write(CSR_HGATP, mode << HGATP_MODE_SHIFT); + return ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == mode); +} + void __init kvm_riscv_gstage_mode_detect(void) { + kvm_riscv_gstage_supported_mode_mask = 0; + kvm_riscv_gstage_max_pgd_levels = 0; + #ifdef CONFIG_64BIT - /* Try Sv57x4 G-stage mode */ - csr_write(CSR_HGATP, HGATP_MODE_SV57X4 << HGATP_MODE_SHIFT); - if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV57X4) { - kvm_riscv_gstage_max_pgd_levels = 5; - goto done; + /* Try Sv39x4 G-stage mode */ + if (kvm_riscv_hgatp_mode_supported(HGATP_MODE_SV39X4)) { + kvm_riscv_gstage_supported_mode_mask |= BIT(HGATP_MODE_SV39X4); + kvm_riscv_gstage_max_pgd_levels = 3; } /* Try Sv48x4 G-stage mode */ - csr_write(CSR_HGATP, HGATP_MODE_SV48X4 << HGATP_MODE_SHIFT); - if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV48X4) { + if (kvm_riscv_hgatp_mode_supported(HGATP_MODE_SV48X4)) { + kvm_riscv_gstage_supported_mode_mask |= BIT(HGATP_MODE_SV48X4); kvm_riscv_gstage_max_pgd_levels = 4; - goto done; } - /* Try Sv39x4 G-stage mode */ - csr_write(CSR_HGATP, HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT); - if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV39X4) { - kvm_riscv_gstage_max_pgd_levels = 3; - goto done; + /* Try Sv57x4 G-stage mode */ + if (kvm_riscv_hgatp_mode_supported(HGATP_MODE_SV57X4)) { + kvm_riscv_gstage_supported_mode_mask |= BIT(HGATP_MODE_SV57X4); + kvm_riscv_gstage_max_pgd_levels = 5; } #else /* CONFIG_32BIT */ /* Try Sv32x4 G-stage mode */ - csr_write(CSR_HGATP, HGATP_MODE_SV32X4 << HGATP_MODE_SHIFT); - if ((csr_read(CSR_HGATP) >> HGATP_MODE_SHIFT) == HGATP_MODE_SV32X4) { + if (kvm_riscv_hgatp_mode_supported(HGATP_MODE_SV32X4)) { + kvm_riscv_gstage_supported_mode_mask |= BIT(HGATP_MODE_SV32X4); kvm_riscv_gstage_max_pgd_levels = 2; - goto done; } #endif - /* KVM depends on !HGATP_MODE_OFF */ - kvm_riscv_gstage_max_pgd_levels = 0; - -done: csr_write(CSR_HGATP, 0); kvm_riscv_local_hfence_gvma_all(); } -- 2.50.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv