From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 8478A213E80; Thu, 20 Feb 2025 21:58:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740088690; cv=none; b=BVmZ60AfJlFphy38jONEKoueN1gb57zHgHUzSPDZ0hiTOfgy87cZ+zz20gVR77eIMrSPBpnvk5d9AZlk0gZ52hFIpLsa6Fd+7pra+3jHObIfZi75BJnq+esIrKu6pDkRbPy/sbTIp8nxW1iN+VRj169gPvtvy+DbzUr7nT07ytI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740088690; c=relaxed/simple; bh=hhd3B8T0Wnd0AA9SKmXe1lAVXaqnnoyajYB/dQyND3w=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YEw/4mnkZ56IQYqFfAPhNAIFsWQHdtvP/0WmrPCQIAcH+eh/R7BCu0A5CM3mZK/ZU6RSpJuMKYZ4xg6L4Hc6u7AERRlxsSE9DISnQlgV7vy3d4+3h7tew8i/k58/QmXNk7sOBza56EmRGNwcTiIvGjYyoaL85k2AuoR71LLDdTQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=dMqCGFVp; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="dMqCGFVp" Received: from [10.0.0.114] (c-67-182-156-199.hsd1.wa.comcast.net [67.182.156.199]) by linux.microsoft.com (Postfix) with ESMTPSA id B044A203E3BD; Thu, 20 Feb 2025 13:58:07 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com B044A203E3BD DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1740088688; bh=8O/BFXNYUlbWqYOn91G8A2mFS2+fXJ+Iw3KR7ydAxqM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=dMqCGFVpL42bwlZlJHMSuTTwuBA/sxgE5feV1M6m3hpmvrJSk5z4htbawHEWqNFb+ pWj/qs0U0ciP09t8y/gqIAQ3YwxGW57AmzxGsELv+wTuzLQ2WQbKBj2YJv6n7+js2g dguZh9PH/E5NOtUatZSDxcL7fFcRCDo5pdM7ku5M= Message-ID: <2b8f135b-8a65-4cee-ba4b-af1cd987c687@linux.microsoft.com> Date: Thu, 20 Feb 2025 13:58:07 -0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/3] hyperv: Convert hypercall statuses to linux error codes To: Michael Kelley , "linux-hyperv@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux-arch@vger.kernel.org" , "iommu@lists.linux.dev" , "eahariha@linux.microsoft.com" Cc: "kys@microsoft.com" , "haiyangz@microsoft.com" , "wei.liu@kernel.org" , "decui@microsoft.com" , "catalin.marinas@arm.com" , "will@kernel.org" , "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "x86@kernel.org" , "hpa@zytor.com" , "daniel.lezcano@linaro.org" , "joro@8bytes.org" , "robin.murphy@arm.com" , "arnd@arndb.de" , "jinankjain@linux.microsoft.com" , "muminulrussell@gmail.com" , "skinsburskii@linux.microsoft.com" , "mukeshrathor@microsoft.com" References: <1740076396-15086-1-git-send-email-nunodasneves@linux.microsoft.com> <1740076396-15086-2-git-send-email-nunodasneves@linux.microsoft.com> Content-Language: en-US From: Nuno Das Neves In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/20/2025 11:03 AM, Michael Kelley wrote: > From: Nuno Das Neves Sent: Thursday, February 20, 2025 10:33 AM >> >> Return linux-friendly error codes from hypercall helper functions, >> which allows them to be used more flexibly. >> >> Introduce hv_result_to_errno() for this purpose, which also handles >> the special value U64_MAX returned from hv_do_hypercall(). >> >> Signed-off-by: Nuno Das Neves >> --- >> drivers/hv/hv_common.c | 34 ++++++++++++++++++++++++++++++++++ >> drivers/hv/hv_proc.c | 6 +++--- >> include/asm-generic/mshyperv.h | 1 + >> 3 files changed, 38 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c >> index ee3083937b4f..2120aead98d9 100644 >> --- a/drivers/hv/hv_common.c >> +++ b/drivers/hv/hv_common.c >> @@ -683,3 +683,37 @@ u64 __weak hv_tdx_hypercall(u64 control, u64 param1, u64 param2) >> return HV_STATUS_INVALID_PARAMETER; >> } >> EXPORT_SYMBOL_GPL(hv_tdx_hypercall); >> + >> +/* Convert a hypercall result into a linux-friendly error code. */ >> +int hv_result_to_errno(u64 status) >> +{ >> + /* hv_do_hypercall() may return U64_MAX, hypercalls aren't possible */ >> + if (unlikely(status == U64_MAX)) >> + return -EOPNOTSUPP; >> + /* >> + * A failed hypercall is usually only recoverable (or loggable) near >> + * the call site where the HV_STATUS_* code is known. So the errno >> + * it gets converted to is not too useful further up the stack. >> + * Provice a few mappings that could be useful, and revert to -EIO >> + * as a fallback. >> + */ >> + switch (hv_result(status)) { >> + case HV_STATUS_SUCCESS: >> + return 0; >> + case HV_STATUS_INVALID_HYPERCALL_CODE: >> + case HV_STATUS_INVALID_HYPERCALL_INPUT: >> + case HV_STATUS_INVALID_PARAMETER: >> + case HV_STATUS_INVALID_PARTITION_ID: >> + case HV_STATUS_INVALID_VP_INDEX: >> + case HV_STATUS_INVALID_PORT_ID: >> + case HV_STATUS_INVALID_CONNECTION_ID: >> + case HV_STATUS_INVALID_LP_INDEX: >> + case HV_STATUS_INVALID_REGISTER_VALUE: >> + return -EINVAL; >> + case HV_STATUS_INSUFFICIENT_MEMORY: >> + return -ENOMEM; >> + default: >> + break; >> + } >> + return -EIO; >> +} >> diff --git a/drivers/hv/hv_proc.c b/drivers/hv/hv_proc.c >> index 3e410489f480..72b09f1cfa3e 100644 >> --- a/drivers/hv/hv_proc.c >> +++ b/drivers/hv/hv_proc.c >> @@ -88,7 +88,7 @@ int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages) >> local_irq_restore(flags); >> if (!hv_result_success(status)) { >> pr_err("Failed to deposit pages: %lld\n", status); >> - ret = hv_result(status); >> + ret = hv_result_to_errno(status); >> goto err_free_allocations; >> } >> >> @@ -139,7 +139,7 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u32 apic_id) >> if (!hv_result_success(status)) { >> pr_err("%s: cpu %u apic ID %u, %lld\n", __func__, >> lp_index, apic_id, status); >> - ret = hv_result(status); >> + ret = hv_result_to_errno(status); >> } >> break; >> } >> @@ -181,7 +181,7 @@ int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags) >> if (!hv_result_success(status)) { >> pr_err("%s: vcpu %u, lp %u, %lld\n", __func__, >> vp_index, flags, status); >> - ret = hv_result(status); >> + ret = hv_result_to_errno(status); >> } >> break; >> } > > In hv_call_add_logical_proc() and hv_call_create_vp(), local variable "ret" is > defined and initialized to HV_STATUS_SUCCESS. Since "ret" now contains an > errno value instead of a hypercall status, it should be initialized to zero. (Yes, > HV_STATUS_SUCCESS is defined as 0, but it's now the wrong abstraction.) > Great point, I'll post a v3 to fix it. > With that fixed, > > Reviewed-by: Michael Kelley > >> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h >> index 7adc10a4fa3e..3f115e2bcdaa 100644 >> --- a/include/asm-generic/mshyperv.h >> +++ b/include/asm-generic/mshyperv.h >> @@ -297,6 +297,7 @@ static inline int cpumask_to_vpset_skip(struct hv_vpset *vpset, >> return __cpumask_to_vpset(vpset, cpus, func); >> } >> >> +int hv_result_to_errno(u64 status); >> void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die); >> bool hv_is_hyperv_initialized(void); >> bool hv_is_hibernation_supported(void); >> -- >> 2.34.1