A guest cannot access quadrants 1 or 2 as this would result in an
exception. Thus introduce the hcall H_COPY_TOFROM_GUEST to be used by a
guest when it wants to perform an access to quadrants 1 or 2, for
example when it wants to access memory for one of its nested guests.
Also provide an implementation for the kvm-hv module.
Signed-off-by: Suraj Jitindar Singh <sjitindarsi...@gmail.com>
---
arch/powerpc/include/asm/hvcall.h | 1 +
arch/powerpc/include/asm/kvm_book3s.h | 4 ++
arch/powerpc/kvm/book3s_64_mmu_radix.c | 7 ++--
arch/powerpc/kvm/book3s_hv.c | 6 ++-
arch/powerpc/kvm/book3s_hv_nested.c | 75 ++++++++++++++++++++++++++++++++++
5 files changed, 89 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/hvcall.h
b/arch/powerpc/include/asm/hvcall.h
index 33a4fc891947..463c63a9fcf1 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -335,6 +335,7 @@
#define H_SET_PARTITION_TABLE 0xF800
#define H_ENTER_NESTED 0xF804
#define H_TLB_INVALIDATE 0xF808
+#define H_COPY_TOFROM_GUEST 0xF80C
/* Values for 2nd argument to H_SET_MODE */
#define H_SET_MODE_RESOURCE_SET_CIABR 1
diff --git a/arch/powerpc/include/asm/kvm_book3s.h
b/arch/powerpc/include/asm/kvm_book3s.h
index ea94110bfde4..720483733bb2 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -188,6 +188,9 @@ extern int kvmppc_book3s_hcall_implemented(struct kvm *kvm,
unsigned long hc);
extern int kvmppc_book3s_radix_page_fault(struct kvm_run *run,
struct kvm_vcpu *vcpu,
unsigned long ea, unsigned long dsisr);
+extern unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
+ gva_t eaddr, void *to, void *from,
+ unsigned long n);
extern long kvmhv_copy_from_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,
void *to, unsigned long n);
extern long kvmhv_copy_to_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,
@@ -302,6 +305,7 @@ long kvmhv_nested_init(void);
void kvmhv_nested_exit(void);
void kvmhv_vm_nested_init(struct kvm *kvm);
long kvmhv_set_partition_table(struct kvm_vcpu *vcpu);
+long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu);
void kvmhv_set_ptbl_entry(unsigned int lpid, u64 dw0, u64 dw1);
void kvmhv_release_all_nested(struct kvm *kvm);
long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu);
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c
b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index e1e3ef710bd0..da89d10e5886 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -29,9 +29,9 @@
*/
static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 };
-static unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
- gva_t eaddr, void *to, void *from,
- unsigned long n)
+unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
+ gva_t eaddr, void *to, void *from,
+ unsigned long n)
{
unsigned long quadrant, ret = n;
int old_pid, old_lpid;
@@ -82,6 +82,7 @@ static unsigned long __kvmhv_copy_tofrom_guest_radix(int
lpid, int pid,
return ret;
}
+EXPORT_SYMBOL_GPL(__kvmhv_copy_tofrom_guest_radix);
static long kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,
void *to, void *from, unsigned long n)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 2280bc4778f5..bd07f9b7c5e8 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -996,7 +996,11 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
if (nesting_enabled(vcpu->kvm))
ret = kvmhv_do_nested_tlbie(vcpu);
break;
-
+ case H_COPY_TOFROM_GUEST:
+ ret = H_FUNCTION;
+ if (nesting_enabled(vcpu->kvm))
+ ret = kvmhv_copy_tofrom_guest_nested(vcpu);
+ break;
default:
return RESUME_HOST;
}
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c
b/arch/powerpc/kvm/book3s_hv_nested.c
index 991f40ce4eea..5903175751b4 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -462,6 +462,81 @@ long kvmhv_set_partition_table(struct kvm_vcpu *vcpu)
}
/*
+ * Handle the H_COPY_TOFROM_GUEST hcall.
+ * r4 = L1 lpid of nested guest
+ * r5 = pid
+ * r6 = eaddr to access
+ * r7 = to buffer (L1 gpa)
+ * r8 = from buffer (L1 gpa)
+ * r9 = n bytes to copy
+ */
+long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu)
+{
+ struct kvm_nested_guest *gp;
+ int l1_lpid = kvmppc_get_gpr(vcpu, 4);
+ int pid = kvmppc_get_gpr(vcpu, 5);
+ gva_t eaddr = kvmppc_get_gpr(vcpu, 6);
+ gpa_t gp_to = (gpa_t) kvmppc_get_gpr(vcpu, 7);
+ gpa_t gp_from = (gpa_t) kvmppc_get_gpr(vcpu, 8);
+ void *buf;
+ unsigned long n = kvmppc_get_gpr(vcpu, 9);
+ bool is_load = !!gp_to;
+ long rc;
+
+ if (gp_to && gp_from) /* One must be NULL to determine the direction */
+ return H_PARAMETER;
+
+ if (eaddr & (0xFFFUL << 52))
+ return H_PARAMETER;
+
+ buf = kzalloc(n, GFP_KERNEL);
+ if (!buf)
+ return H_NO_MEM;
+
+ gp = kvmhv_get_nested(vcpu->kvm, l1_lpid, false);
+ if (!gp) {
+ rc = H_PARAMETER;
+ goto out_free;
+ }
+
+ mutex_lock(&gp->tlb_lock);
+
+ if (is_load) {
+ /* Load from the nested guest into our buffer */
+ rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,
+ eaddr, buf, NULL, n);
+ if (rc)
+ goto not_found;
+
+ /* Write what was loaded into our buffer back to the L1 guest */
+ rc = kvm_vcpu_write_guest(vcpu, gp_to, buf, n);
+ if (rc)
+ goto not_found;
+ } else {
+ /* Load the data to be stored from the L1 guest into our buf */
+ rc = kvm_vcpu_read_guest(vcpu, gp_from, buf, n);
+ if (rc)
+ goto not_found;
+
+ /* Store from our buffer into the nested guest */
+ rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,
+ eaddr, NULL, buf, n);
+ if (rc)
+ goto not_found;
+ }
+
+out_unlock:
+ mutex_unlock(&gp->tlb_lock);
+ kvmhv_put_nested(gp);
+out_free:
+ kfree(buf);
+ return rc;
+not_found:
+ rc = H_NOT_FOUND;
+ goto out_unlock;
+}
+
+/*
* Reload the partition table entry for a guest.
* Caller must hold gp->tlb_lock.
*/
--
2.13.6
