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From: Alexey Kardashevskiy <aik@ozlabs.ru>
To: linuxppc-dev@lists.ozlabs.org
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>,
	Michael Anderson <andmike@linux.ibm.com>,
	Ram Pai <linuxram@us.ibm.com>,
	kvm-ppc@vger.kernel.org,
	Thiago Jung Bauermann <bauerman@linux.ibm.com>,
	David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH kernel v2 4/4] powerpc/pseries/svm: Allow IOMMU to work in SVM
Date: Mon, 16 Dec 2019 15:19:24 +1100	[thread overview]
Message-ID: <20191216041924.42318-5-aik@ozlabs.ru> (raw)
In-Reply-To: <20191216041924.42318-1-aik@ozlabs.ru>

H_PUT_TCE_INDIRECT uses a shared page to send up to 512 TCE to
a hypervisor in a single hypercall. This does not work for secure VMs
as the page needs to be shared or the VM should use H_PUT_TCE instead.

This disables H_PUT_TCE_INDIRECT by clearing the FW_FEATURE_PUT_TCE_IND
feature bit so SVMs will map TCEs using H_PUT_TCE.

This is not a part of init_svm() as it is called too late after FW
patching is done and may result in a warning like this:

[    3.727716] Firmware features changed after feature patching!
[    3.727965] WARNING: CPU: 0 PID: 1 at (...)arch/powerpc/lib/feature-fixups.c:466 check_features+0xa4/0xc0

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v2
* new in the patchset
---
 arch/powerpc/platforms/pseries/firmware.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/firmware.c b/arch/powerpc/platforms/pseries/firmware.c
index d3acff23f2e3..3e49cc23a97a 100644
--- a/arch/powerpc/platforms/pseries/firmware.c
+++ b/arch/powerpc/platforms/pseries/firmware.c
@@ -22,6 +22,7 @@
 #include <asm/firmware.h>
 #include <asm/prom.h>
 #include <asm/udbg.h>
+#include <asm/svm.h>
 
 #include "pseries.h"
 
@@ -101,6 +102,12 @@ static void __init fw_hypertas_feature_init(const char *hypertas,
 		}
 	}
 
+	if (is_secure_guest() &&
+	    (powerpc_firmware_features & FW_FEATURE_PUT_TCE_IND)) {
+		powerpc_firmware_features &= ~FW_FEATURE_PUT_TCE_IND;
+		pr_debug("SVM: disabling PUT_TCE_IND firmware feature\n");
+	}
+
 	pr_debug(" <- fw_hypertas_feature_init()\n");
 }
 
-- 
2.17.1


  parent reply	other threads:[~2019-12-16  4:29 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-16  4:19 [PATCH kernel v2 0/4] Enable IOMMU support for pseries Secure VMs Alexey Kardashevskiy
2019-12-16  4:19 ` [PATCH kernel v2 1/4] Revert "powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests" Alexey Kardashevskiy
2019-12-16 22:58   ` Thiago Jung Bauermann
2020-01-06 23:33   ` Michael Ellerman
2019-12-16  4:19 ` [PATCH kernel v2 2/4] powerpc/pseries: Allow not having ibm, hypertas-functions::hcall-multi-tce for DDW Alexey Kardashevskiy
2019-12-16 23:07   ` Thiago Jung Bauermann
2019-12-17  0:09     ` [PATCH kernel v2 2/4] powerpc/pseries: Allow not having ibm,hypertas-functions::hcall-multi-tce " Alexey Kardashevskiy
2019-12-17  2:06       ` [PATCH kernel v2 2/4] powerpc/pseries: Allow not having ibm, hypertas-functions::hcall-multi-tce " Thiago Jung Bauermann
2020-01-02 22:02   ` [PATCH kernel v2 2/4] powerpc/pseries: Allow not having ibm,hypertas-functions::hcall-multi-tce " Ram Pai
2019-12-16  4:19 ` [PATCH kernel v2 3/4] powerpc/pseries/iommu: Separate FW_FEATURE_MULTITCE to put/stuff features Alexey Kardashevskiy
2019-12-16 23:19   ` Thiago Jung Bauermann
2020-01-02 22:24   ` Ram Pai
2019-12-16  4:19 ` Alexey Kardashevskiy [this message]
2019-12-16 23:23   ` [PATCH kernel v2 4/4] powerpc/pseries/svm: Allow IOMMU to work in SVM Thiago Jung Bauermann
2020-01-02 22:21   ` Ram Pai
2020-01-03  0:08     ` David Gibson
2020-01-03  2:06       ` Ram Pai

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