From patchwork Wed Jul 27 14:32:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Ellerman X-Patchwork-Id: 1661271 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=QEftNBnW; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4LtGV70sDSz9sFk for ; Thu, 28 Jul 2022 00:33:19 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4LtGV66sWVz3dr4 for ; Thu, 28 Jul 2022 00:33:18 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=QEftNBnW; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4LtGTH1GHYz3c1S for ; Thu, 28 Jul 2022 00:32:35 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=QEftNBnW; dkim-atps=neutral Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4LtGTC60pkz4x1b; Thu, 28 Jul 2022 00:32:31 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1658932351; bh=eWPRA26XDel52hhEw2dbbtl/aQB2F2Au98GF0XPWltw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QEftNBnWJ1nARnyto2ODpK1S5fHWO8smWtsK0q/bYlu3gp4igpayIxL0kRCEB7kFy rtn5oELZUAdCHCrVBoNszZuLblJxf88HVuFkqrkWf8C9ryh6ju5mkyjjD3i/Ys8N80 g/NoSxeVg4mt4OGR97Krmraw1aDe/6KlK38VEximy0A8PggEW1Y3AEQL/46wosskrO HcpsxqgbLjCFzr+Az0XGLzu7JYpZO7SEi5C2gZQegK7U6n5Rz/ry8DvYhYGCOa6VP/ rwNwTKGBBSTf5+9MOU/70vjfFEXj1nKQW5pEq2l25Fi3edpCsK48djIGonpQeA5hEo vUg4x1vmpodGQ== From: Michael Ellerman To: Subject: [PATCH v6 2/3] powerpc/powernv/kvm: Use darn for H_RANDOM on Power9 Date: Thu, 28 Jul 2022 00:32:18 +1000 Message-Id: <20220727143219.2684192-2-mpe@ellerman.id.au> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220727143219.2684192-1-mpe@ellerman.id.au> References: <20220727143219.2684192-1-mpe@ellerman.id.au> MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jason@zx2c4.com Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: "Jason A. Donenfeld" The existing logic in KVM to support guests calling H_RANDOM only works on Power8, because it looks for an RNG in the device tree, but on Power9 we just use darn. In addition the existing code needs to work in real mode, so we have the special cased powernv_get_random_real_mode() to deal with that. Instead just have KVM call ppc_md.get_random_seed(), and do the real mode check inside of there, that way we use whatever RNG is available, including darn on Power9. Cc: stable@vger.kernel.org # v4.1+ Tested-by: Sachin Sant Fixes: e928e9cb3601 ("KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation.") Signed-off-by: Jason A. Donenfeld [mpe: Rebase on previous commit, update change log appropriately] Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/archrandom.h | 5 ---- arch/powerpc/kvm/book3s_hv_builtin.c | 7 +++--- arch/powerpc/platforms/powernv/rng.c | 36 ++++++--------------------- 3 files changed, 12 insertions(+), 36 deletions(-) v6: Rebased on previous fix commit. diff --git a/arch/powerpc/include/asm/archrandom.h b/arch/powerpc/include/asm/archrandom.h index 9a53e29680f4..258174304904 100644 --- a/arch/powerpc/include/asm/archrandom.h +++ b/arch/powerpc/include/asm/archrandom.h @@ -38,12 +38,7 @@ static inline bool __must_check arch_get_random_seed_int(unsigned int *v) #endif /* CONFIG_ARCH_RANDOM */ #ifdef CONFIG_PPC_POWERNV -int powernv_hwrng_present(void); int powernv_get_random_long(unsigned long *v); -int powernv_get_random_real_mode(unsigned long *v); -#else -static inline int powernv_hwrng_present(void) { return 0; } -static inline int powernv_get_random_real_mode(unsigned long *v) { return 0; } #endif #endif /* _ASM_POWERPC_ARCHRANDOM_H */ diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c index 88a8f6473c4e..3abaef5f9ac2 100644 --- a/arch/powerpc/kvm/book3s_hv_builtin.c +++ b/arch/powerpc/kvm/book3s_hv_builtin.c @@ -19,7 +19,7 @@ #include #include #include -#include +#include #include #include #include @@ -176,13 +176,14 @@ EXPORT_SYMBOL_GPL(kvmppc_hcall_impl_hv_realmode); int kvmppc_hwrng_present(void) { - return powernv_hwrng_present(); + return ppc_md.get_random_seed != NULL; } EXPORT_SYMBOL_GPL(kvmppc_hwrng_present); long kvmppc_rm_h_random(struct kvm_vcpu *vcpu) { - if (powernv_get_random_real_mode(&vcpu->arch.regs.gpr[4])) + if (ppc_md.get_random_seed && + ppc_md.get_random_seed(&vcpu->arch.regs.gpr[4])) return H_SUCCESS; return H_HARDWARE; diff --git a/arch/powerpc/platforms/powernv/rng.c b/arch/powerpc/platforms/powernv/rng.c index 2287c9cd0cd5..d19305292e1e 100644 --- a/arch/powerpc/platforms/powernv/rng.c +++ b/arch/powerpc/platforms/powernv/rng.c @@ -29,15 +29,6 @@ struct powernv_rng { static DEFINE_PER_CPU(struct powernv_rng *, powernv_rng); -int powernv_hwrng_present(void) -{ - struct powernv_rng *rng; - - rng = get_cpu_var(powernv_rng); - put_cpu_var(rng); - return rng != NULL; -} - static unsigned long rng_whiten(struct powernv_rng *rng, unsigned long val) { unsigned long parity; @@ -58,19 +49,6 @@ static unsigned long rng_whiten(struct powernv_rng *rng, unsigned long val) return val; } -int powernv_get_random_real_mode(unsigned long *v) -{ - struct powernv_rng *rng; - - rng = raw_cpu_read(powernv_rng); - if (!rng) - return 0; - - *v = rng_whiten(rng, __raw_rm_readq(rng->regs_real)); - - return 1; -} - static int powernv_get_random_darn(unsigned long *v) { unsigned long val; @@ -107,12 +85,14 @@ int powernv_get_random_long(unsigned long *v) { struct powernv_rng *rng; - rng = get_cpu_var(powernv_rng); - - *v = rng_whiten(rng, in_be64(rng->regs)); - - put_cpu_var(rng); - + if (mfmsr() & MSR_DR) { + rng = get_cpu_var(powernv_rng); + *v = rng_whiten(rng, in_be64(rng->regs)); + put_cpu_var(rng); + } else { + rng = raw_cpu_read(powernv_rng); + *v = rng_whiten(rng, __raw_rm_readq(rng->regs_real)); + } return 1; } EXPORT_SYMBOL_GPL(powernv_get_random_long);