kernel.git/arch/powerpc/include/asm/svm.h, branch linux-5.13.y

powerpc/pseries/svm: Allocate SWIOTLB buffer anywhere in memory

2020-09-14T13:07:14Z

POWER secure guests (i.e., guests which use the Protected Execution Facility) need to use SWIOTLB to be able to do I/O with the hypervisor, but they don't need the SWIOTLB memory to be in low addresses since the hypervisor doesn't have any addressing limitation. This solves a SWIOTLB initialization problem we are seeing in secure guests with 128 GB of RAM: they are configured with 4 GB of crashkernel reserved memory, which leaves no space for SWIOTLB in low addresses. To do this, we use mostly the same code as swiotlb_init(), but allocate the buffer using memblock_alloc() instead of memblock_alloc_low(). Fixes: 2efbc58f157a ("powerpc/pseries/svm: Force SWIOTLB for secure guests") Signed-off-by: Thiago Jung Bauermann Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200818221126.391073-1-bauerman@linux.ibm.com

powerpc/pseries/svm: Use shared memory for Debug Trace Log (DTL)

2019-08-29T23:55:40Z

Secure guests need to share the DTL buffers with the hypervisor. To that end, use a kmem_cache constructor which converts the underlying buddy allocated SLUB cache pages into shared memory. Signed-off-by: Anshuman Khandual Signed-off-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190820021326.6884-10-bauerman@linux.ibm.com

powerpc/pseries/svm: Use shared memory for LPPACA structures

2019-08-29T23:55:40Z

LPPACA structures need to be shared with the host. Hence they need to be in shared memory. Instead of allocating individual chunks of memory for a given structure from memblock, a contiguous chunk of memory is allocated and then converted into shared memory. Subsequent allocation requests will come from the contiguous chunk which will be always shared memory for all structures. While we are able to use a kmem_cache constructor for the Debug Trace Log, LPPACAs are allocated very early in the boot process (before SLUB is available) so we need to use a simpler scheme here. Introduce helper is_svm_platform() which uses the S bit of the MSR to tell whether we're running as a secure guest. Signed-off-by: Anshuman Khandual Signed-off-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190820021326.6884-9-bauerman@linux.ibm.com