RISC-V: KVM: Fix guest page fault within HLV* instructions

RISC-V: KVM: Fix guest page fault within HLV* instructions

[ Upstream commit 974555d6e417974e63444266e495a06d06c23af5 ]

When executing HLV* instructions at the HS mode, a guest page fault
may occur when a g-stage page table migration between triggering the
virtual instruction exception and executing the HLV* instruction.

This may be a corner case, and one simpler way to handle this is to
re-execute the instruction where the virtual  instruction exception
occurred, and the guest page fault will be automatically handled.

Fixes: b91f0e4cb8a3 ("RISC-V: KVM: Factor-out instruction emulation into separate sources")
Signed-off-by: Fangyu Yu <fangyu.yu@linux.alibaba.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20251121133543.46822-1-fangyu.yu@linux.alibaba.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>