From patchwork Wed Jan 10 23:13:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Atish Kumar Patra X-Patchwork-Id: 13516662 Received: from mail-io1-f46.google.com (mail-io1-f46.google.com [209.85.166.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CDF3053E0C for ; Wed, 10 Jan 2024 23:14:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b="eCWzhj5L" Received: by mail-io1-f46.google.com with SMTP id ca18e2360f4ac-7beda2e6794so83442839f.1 for ; Wed, 10 Jan 2024 15:14:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1704928489; x=1705533289; darn=vger.kernel.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=C8UQElc6A/TnygdjzPZGFQnFIW5Dl3R45uxNNmzEmHk=; b=eCWzhj5LOlysgilm3p3hoM2D6KFD4eZx5vjCAdgZmv9fXKg5cC6DTnyzktH5eTGYPp 2KFozmFlEzQx9820ultnJlepmnlZErDbSfQXFbCZEWyB5xqrDvht6hFB6I6iTuDvZ0Wi 7bTFuZyanR9KlZNxhpfHvPIjMQ3iSZjnPPdb9c3UoV528pQPG9DrpKtg0i5BiouP17+z 3r+mzQmo3GsbzaT4hLauWlv3g2LN2OqvzlVFHQun3N0rHfIBCLY9r6OmnpVFtTWD8tGm C7biSi1SmRqwtAPoQWBwmet5iCa9HM5KQlg1czEbVtmB8Wm+UGueO6UxWKHyCtjdeU12 9oAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1704928489; x=1705533289; 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=C8UQElc6A/TnygdjzPZGFQnFIW5Dl3R45uxNNmzEmHk=; b=uLt0xtzpJv4ywhxrwEI8wds8xoIuERFb6eZBq7EpLUZrUa3AT6oA+F9+NTf34cTjne 9RPsugytdH0nl6kRUqg1QGYVsXFDhjDM74ZeGnnpfQZwM+OM0G0FiXXSrsIOA/NK6y2l mH4i+0+4hDKb7BMg7jQMZn0kgROiexB/x9nokh8/rGk9PONw81xeIn5fPFz75Jn/B9ZS shdc+AzH8PLnxqZNQx5Dsz0e6DNLzyBlROu25eYusrzFVibH8CxSzzXME1zP/2M1OJ52 qnC6Tv1y4xWu+YUFl8PAENH/y/JB9PGV4LNCq6vYvSqB2jVJDS60q8USyX4yLUsaT2wf 25/Q== X-Gm-Message-State: AOJu0YwWJCqX6TUmkRIe5vx2V8ytyXtrGK07hw1IbRx8Ty8toS7OUkHK KfhpRj/iAneCCPFnKhS094v49uN+xEW91g== X-Google-Smtp-Source: AGHT+IF5V83U/JpKcG4G+2/kPT0mLzMy58MOJPAO3gRWS2gTlupn43hdpcod+XzgEM0PaED9NMpmPQ== X-Received: by 2002:a5e:c748:0:b0:7be:c0d4:f567 with SMTP id g8-20020a5ec748000000b007bec0d4f567mr677989iop.4.1704928488783; Wed, 10 Jan 2024 15:14:48 -0800 (PST) Received: from atishp.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id co13-20020a0566383e0d00b0046e3b925818sm1185503jab.37.2024.01.10.15.14.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Jan 2024 15:14:48 -0800 (PST) From: Atish Patra To: linux-kernel@vger.kernel.org Cc: Atish Patra , Anup Patel , Alexandre Ghiti , Andrew Jones , Atish Patra , Conor Dooley , Guo Ren , Icenowy Zheng , kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-riscv@lists.infradead.org, Mark Rutland , Palmer Dabbelt , Paul Walmsley , Will Deacon , Vladimir Isaev Subject: [v3 07/10] RISC-V: KVM: No need to exit to the user space if perf event failed Date: Wed, 10 Jan 2024 15:13:56 -0800 Message-Id: <20240110231359.1239367-8-atishp@rivosinc.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240110231359.1239367-1-atishp@rivosinc.com> References: <20240110231359.1239367-1-atishp@rivosinc.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Currently, we return a linux error code if creating a perf event failed in kvm. That shouldn't be necessary as guest can continue to operate without perf profiling or profiling with firmware counters. Return appropriate SBI error code to indicate that PMU configuration failed. An error message in kvm already describes the reason for failure. Fixes: 0cb74b65d2e5 ("RISC-V: KVM: Implement perf support without sampling") Reviewed-by: Anup Patel Signed-off-by: Atish Patra --- arch/riscv/kvm/vcpu_pmu.c | 14 +++++++++----- arch/riscv/kvm/vcpu_sbi_pmu.c | 6 +++--- 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c index b1574c043f77..29bf4ca798cb 100644 --- a/arch/riscv/kvm/vcpu_pmu.c +++ b/arch/riscv/kvm/vcpu_pmu.c @@ -229,8 +229,9 @@ static int kvm_pmu_validate_counter_mask(struct kvm_pmu *kvpmu, unsigned long ct return 0; } -static int kvm_pmu_create_perf_event(struct kvm_pmc *pmc, struct perf_event_attr *attr, - unsigned long flags, unsigned long eidx, unsigned long evtdata) +static long kvm_pmu_create_perf_event(struct kvm_pmc *pmc, struct perf_event_attr *attr, + unsigned long flags, unsigned long eidx, + unsigned long evtdata) { struct perf_event *event; @@ -454,7 +455,8 @@ int kvm_riscv_vcpu_pmu_ctr_cfg_match(struct kvm_vcpu *vcpu, unsigned long ctr_ba unsigned long eidx, u64 evtdata, struct kvm_vcpu_sbi_return *retdata) { - int ctr_idx, ret, sbiret = 0; + int ctr_idx, sbiret = 0; + long ret; bool is_fevent; unsigned long event_code; u32 etype = kvm_pmu_get_perf_event_type(eidx); @@ -513,8 +515,10 @@ int kvm_riscv_vcpu_pmu_ctr_cfg_match(struct kvm_vcpu *vcpu, unsigned long ctr_ba kvpmu->fw_event[event_code].started = true; } else { ret = kvm_pmu_create_perf_event(pmc, &attr, flags, eidx, evtdata); - if (ret) - return ret; + if (ret) { + sbiret = SBI_ERR_NOT_SUPPORTED; + goto out; + } } set_bit(ctr_idx, kvpmu->pmc_in_use); diff --git a/arch/riscv/kvm/vcpu_sbi_pmu.c b/arch/riscv/kvm/vcpu_sbi_pmu.c index 7eca72df2cbd..b70179e9e875 100644 --- a/arch/riscv/kvm/vcpu_sbi_pmu.c +++ b/arch/riscv/kvm/vcpu_sbi_pmu.c @@ -42,9 +42,9 @@ static int kvm_sbi_ext_pmu_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, #endif /* * This can fail if perf core framework fails to create an event. - * Forward the error to userspace because it's an error which - * happened within the host kernel. The other option would be - * to convert to an SBI error and forward to the guest. + * No need to forward the error to userspace and exit the guest + * operation can continue without profiling. Forward the + * appropriate SBI error to the guest. */ ret = kvm_riscv_vcpu_pmu_ctr_cfg_match(vcpu, cp->a0, cp->a1, cp->a2, cp->a3, temp, retdata);