KVM: arm64: Don't map 'kvm_vgic_global_state' at EL2 with pKVM

Now that 'kvm_vgic_global_state' is no longer needed for ICC_CTLR_EL1
emulation on machines with a broken SEIS implementation, drop the
pKVM hypervisor mapping of the page.

Note that kvm_vgic_global_state is still mapped in non-protected
hypervisor configurations (i.e. {n,h}VHE) through the rodata section
mapping.

Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241022144016.27350-3-will@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

Author: willdeacon

arch/arm64/kvm/hyp/nvhe/setup.c

@@ -95,7 +95,6 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
 {
 	void *start, *end, *virt = hyp_phys_to_virt(phys);
 	unsigned long pgt_size = hyp_s1_pgtable_pages() << PAGE_SHIFT;
-	enum kvm_pgtable_prot prot;
 	int ret, i;
 
 	/* Recreate the hyp page-table using the early page allocator */
@@ -148,22 +147,6 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
 	}
 
 	pkvm_create_host_sve_mappings();
-
-	/*
-	 * Map the host sections RO in the hypervisor, but transfer the
-	 * ownership from the host to the hypervisor itself to make sure they
-	 * can't be donated or shared with another entity.
-	 *
-	 * The ownership transition requires matching changes in the host
-	 * stage-2. This will be done later (see finalize_host_mappings()) once
-	 * the hyp_vmemmap is addressable.
-	 */
-	prot = pkvm_mkstate(PAGE_HYP_RO, PKVM_PAGE_SHARED_OWNED);
-	ret = pkvm_create_mappings(&kvm_vgic_global_state,
-				   &kvm_vgic_global_state + 1, prot);
-	if (ret)
-		return ret;
-
 	return 0;
 }