Hi,
On 6/12/24 05:40, Jean-Philippe Brucker wrote:
On Wed, Jun 05, 2024 at 10:29:54AM +0100, Steven Price wrote:
From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Detect that the VM is a realm guest by the presence of the RSI
interface.
If in a realm then all memory needs to be marked as RIPAS RAM initially,
the loader may or may not have done this for us. To be sure iterate over
all RAM and mark it as such. Any failure is fatal as that implies the
RAM regions passed to Linux are incorrect - which would mean failing
later when attempting to access non-existent RAM.
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Co-developed-by: Steven Price <steven.price@xxxxxxx>
Signed-off-by: Steven Price <steven.price@xxxxxxx>
+static bool rsi_version_matches(void)
+{
+ unsigned long ver_lower, ver_higher;
+ unsigned long ret = rsi_request_version(RSI_ABI_VERSION,
+ &ver_lower,
+ &ver_higher);
There is a regression on QEMU TCG (in emulation mode, not running under KVM):
qemu-system-aarch64 -M virt -cpu max -kernel Image -nographic
This doesn't implement EL3 or EL2, so SMC is UNDEFINED (DDI0487J.a R_HMXQS),
and we end up with an undef instruction exception. So this patch would
also break hardware that only implements EL1 (I don't know if it exists).
To note: i've found out the hard way this set breaks a qemu+kvm+ACPI
setup as well, for roughly the same reason. I imagine we want kernels
which can boot in either a realm or a normal guest.
I delayed the version check a bit and then, did enough that
arm_smcccc_1_1_invoke() could replace arm_smccc_smc() in
invoke_rsi_fn_smc_with_res(). Which naturally gets it booting again, the
larger implications i've not considered yet.
The easiest fix is to detect the SMC conduit through the PSCI node in DT.
SMCCC helpers already do this, but we can't use them this early in the
boot. I tested adding an early probe to the PSCI driver to check this, see
attached patches.
Note that we do need to test the conduit after finding a PSCI node,
because even though it doesn't implement EL2 in this configuration, QEMU
still accepts PSCI HVCs in order to support SMP.
Thanks,
Jean
