On Mon, Jul 01, 2024 at 10:55:02AM +0100, Steven Price wrote: > Within a realm guest the ITS is emulated by the host. This means the > allocations must have been made available to the host by a call to > set_memory_decrypted(). Introduce an allocation function which performs > this extra call. > > For the ITT use a custom genpool-based allocator that calls > set_memory_decrypted() for each page allocated, but then suballocates > the size needed for each ITT. Note that there is no mechanism > implemented to return pages from the genpool, but it is unlikely the > peak number of devices will so much larger than the normal level - so > this isn't expected to be an issue. > > Co-developed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx> > Signed-off-by: Steven Price <steven.price@xxxxxxx> > --- > Changes since v3: > * Use BIT() macro. > * Use a genpool based allocator in its_create_device() to avoid > allocating a full page. > * Fix subject to drop "realm" and use gic-v3-its. > * Add error handling to ITS alloc/free. > Changes since v2: > * Drop 'shared' from the new its_xxx function names as they are used > for non-realm guests too. > * Don't handle the NUMA_NO_NODE case specially - alloc_pages_node() > should do the right thing. > * Drop a pointless (void *) cast. > --- > drivers/irqchip/irq-gic-v3-its.c | 139 ++++++++++++++++++++++++++----- > 1 file changed, 116 insertions(+), 23 deletions(-) I gave this (and the following patch) a spin in a protected guest under pKVM and was able to use MSIs for my virtio devices, so: Tested-by: Will Deacon <will@xxxxxxxxxx> Will
