KVM: arm64: Factor out stage 2 page table data from struct kvm

As we are about to reuse our stage 2 page table manipulation code for
shadow stage 2 page tables in the context of nested virtualization, we
are going to manage multiple stage 2 page tables for a single VM.

This requires some pretty invasive changes to our data structures,
which moves the vmid and pgd pointers into a separate structure and
change pretty much all of our mmu code to operate on this structure
instead.

The new structure is called struct kvm_s2_mmu.

There is no intended functional change by this patch alone.

Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
[Designed data structure layout in collaboration]
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Co-developed-by: Marc Zyngier <maz@kernel.org>
[maz: Moved the last_vcpu_ran down to the S2 MMU structure as well]
Signed-off-by: Marc Zyngier <maz@kernel.org>

1 files changed, 25 insertions, 7 deletions

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index e0920df1d0c1..85a529eeeae3 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -66,19 +66,34 @@ struct kvm_vmid {
 	u32    vmid;
 };
 
-struct kvm_arch {
+struct kvm_s2_mmu {
 	struct kvm_vmid vmid;
 
-	/* stage2 entry level table */
-	pgd_t *pgd;
-	phys_addr_t pgd_phys;
-
-	/* VTCR_EL2 value for this VM */
-	u64    vtcr;
+	/*
+	 * stage2 entry level table
+	 *
+	 * Two kvm_s2_mmu structures in the same VM can point to the same
+	 * pgd here.  This happens when running a guest using a
+	 * translation regime that isn't affected by its own stage-2
+	 * translation, such as a non-VHE hypervisor running at vEL2, or
+	 * for vEL1/EL0 with vHCR_EL2.VM == 0.  In that case, we use the
+	 * canonical stage-2 page tables.
+	 */
+	pgd_t		*pgd;
+	phys_addr_t	pgd_phys;
 
 	/* The last vcpu id that ran on each physical CPU */
 	int __percpu *last_vcpu_ran;
 
+	struct kvm *kvm;
+};
+
+struct kvm_arch {
+	struct kvm_s2_mmu mmu;
+
+	/* VTCR_EL2 value for this VM */
+	u64    vtcr;
+
 	/* The maximum number of vCPUs depends on the used GIC model */
 	int max_vcpus;
 
@@ -254,6 +269,9 @@ struct kvm_vcpu_arch {
 	void *sve_state;
 	unsigned int sve_max_vl;
 
+	/* Stage 2 paging state used by the hardware on next switch */
+	struct kvm_s2_mmu *hw_mmu;
+
 	/* HYP configuration */
 	u64 hcr_el2;
 	u32 mdcr_el2;