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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Borislav Petkov <bp@suse.de>,
        Tony Luck <tony.luck@intel.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.12 227/700] EDAC/Intel: Do not load EDAC driver when running as a guest
Date:   Mon, 12 Jul 2021 08:05:10 +0200
Message-Id: <20210712060958.921382590@linuxfoundation.org>
In-Reply-To: <20210712060924.797321836@linuxfoundation.org>
References: <20210712060924.797321836@linuxfoundation.org>
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From: Luck, Tony <tony.luck@intel.com>

[ Upstream commit f0a029fff4a50eb01648810a77ba1873e829fdd4 ]

There's little to no point in loading an EDAC driver running in a guest:
1) The CPU model reported by CPUID may not represent actual h/w
2) The hypervisor likely does not pass in access to memory controller devices
3) Hypervisors generally do not pass corrected error details to guests

Add a check in each of the Intel EDAC drivers for X86_FEATURE_HYPERVISOR
and simply return -ENODEV in the init routine.

Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20210615174419.GA1087688@agluck-desk2.amr.corp.intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/edac/i10nm_base.c | 3 +++
 drivers/edac/pnd2_edac.c  | 3 +++
 drivers/edac/sb_edac.c    | 3 +++
 drivers/edac/skx_base.c   | 3 +++
 4 files changed, 12 insertions(+)

diff --git a/drivers/edac/i10nm_base.c b/drivers/edac/i10nm_base.c
index 238a4ad1e526..37b4e875420e 100644
--- a/drivers/edac/i10nm_base.c
+++ b/drivers/edac/i10nm_base.c
@@ -278,6 +278,9 @@ static int __init i10nm_init(void)
 	if (owner && strncmp(owner, EDAC_MOD_STR, sizeof(EDAC_MOD_STR)))
 		return -EBUSY;
 
+	if (cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
+		return -ENODEV;
+
 	id = x86_match_cpu(i10nm_cpuids);
 	if (!id)
 		return -ENODEV;
diff --git a/drivers/edac/pnd2_edac.c b/drivers/edac/pnd2_edac.c
index 928f63a374c7..c94ca1f790c4 100644
--- a/drivers/edac/pnd2_edac.c
+++ b/drivers/edac/pnd2_edac.c
@@ -1554,6 +1554,9 @@ static int __init pnd2_init(void)
 	if (owner && strncmp(owner, EDAC_MOD_STR, sizeof(EDAC_MOD_STR)))
 		return -EBUSY;
 
+	if (cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
+		return -ENODEV;
+
 	id = x86_match_cpu(pnd2_cpuids);
 	if (!id)
 		return -ENODEV;
diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c
index 93daa4297f2e..4c626fcd4dcb 100644
--- a/drivers/edac/sb_edac.c
+++ b/drivers/edac/sb_edac.c
@@ -3510,6 +3510,9 @@ static int __init sbridge_init(void)
 	if (owner && strncmp(owner, EDAC_MOD_STR, sizeof(EDAC_MOD_STR)))
 		return -EBUSY;
 
+	if (cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
+		return -ENODEV;
+
 	id = x86_match_cpu(sbridge_cpuids);
 	if (!id)
 		return -ENODEV;
diff --git a/drivers/edac/skx_base.c b/drivers/edac/skx_base.c
index 6a4f0b27c654..4dbd46575bfb 100644
--- a/drivers/edac/skx_base.c
+++ b/drivers/edac/skx_base.c
@@ -656,6 +656,9 @@ static int __init skx_init(void)
 	if (owner && strncmp(owner, EDAC_MOD_STR, sizeof(EDAC_MOD_STR)))
 		return -EBUSY;
 
+	if (cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
+		return -ENODEV;
+
 	id = x86_match_cpu(skx_cpuids);
 	if (!id)
 		return -ENODEV;
-- 
2.30.2