On SNP-enabled system, VMRUN marks AVIC Backing Page as in-use while
the guest is running for both secure and non-secure guest. Any hypervisor
write to the in-use vCPU's AVIC backing page (e.g. to inject an interrupt)
will generate unexpected #PF in the host.
Currently, attempt to run AVIC guest would result in the following error:
BUG: unable to handle page fault for address: ff3a442e549cc270
#PF: supervisor write access in kernel mode
#PF: error_code(0x80000003) - RMP violation
PGD b6ee01067 P4D b6ee02067 PUD 10096d063 PMD 11c540063 PTE 80000001149cc163
SEV-SNP: PFN 0x1149cc unassigned, dumping non-zero entries in 2M PFN region: [0x114800 - 0x114a00]
...
Newer AMD system is enhanced to allow hypervisor to modify the backing page
for non-secure guest on SNP-enabled system. This enhancement is available
when the CPUID Fn8000_001F_EAX bit 30 is set (HvInUseWrAllowed).
This table describes AVIC support matrix w.r.t. SNP enablement:
| Non-SNP system | SNP system
-----------------------------------------------------
Non-SNP guest | AVIC Activate | AVIC Activate iff
| | HvInuseWrAllowed=1
-----------------------------------------------------
SNP guest | N/A | Secure AVIC
Therefore, check and disable AVIC in kvm_amd driver when the feature is not
available on SNP-enabled system.
See the AMD64 Architecture Programmer’s Manual (APM) Volume 2 for detail.
(https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/
programmer-references/40332.pdf)
Fixes: 216d106c7f ("x86/sev: Add SEV-SNP host initialization support")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20241104075845.7583-1-suravee.suthikulpanit@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
With DT properties charge-current-limit-gpios and
charge-current-limit-mapping one can define charge current limits in uA
using up to 32 GPIOs. At the moment the driver defaults to smallest charge
current limitation for safety reasons. When disabling charging is
supported, which should be common, the driver defaults to non charging on
probe. By having a default, charging can be enabled on probe for such
devices.
Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
Link: https://lore.kernel.org/r/20241218-default-charge-current-limit-v3-2-b26118cf06b5@liebherr.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
With DT properties charge-current-limit-gpios and
charge-current-limit-mapping one can define charge current limits in uA
using up to 32 GPIOs. Add property charge-current-limit-default-microamp
which selects a default charge current limit that must be listed in
charge-current-limit-mapping.
This is helpful when the smallest possible charge current limit is 0uA. The
driver defaults to the smallest possible value at the moment, which
disables charging on probe. With the default its possible to setup a safe
charge current limit.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
Link: https://lore.kernel.org/r/20241218-default-charge-current-limit-v3-1-b26118cf06b5@liebherr.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
