Mailing List Archive

From: Paul Durrant <pdurrant@amazon.com>

This patch moves the implementation of HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE/LIST
that is currently inline in viridian_hypercall() into a new hvcall_flush()
function.

The new function returns Xen erro values which are then dealt with
appropriately. A return value of -ERESTART translates to viridian_hypercall()
returning HVM_HCALL_preempted. Other return values translate to status codes
and viridian_hypercall() returning HVM_HCALL_completed. Currently the only
values, other than -ERESTART, returned by hvcall_flush() are 0 (indicating
success) or -EINVAL.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---
Cc: Wei Liu <wl@xen.org>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>

v3:
- Adjust prototype of new function
---
xen/arch/x86/hvm/viridian/viridian.c | 130 ++++++++++++++++-----------
1 file changed, 78 insertions(+), 52 deletions(-)

diff --git a/xen/arch/x86/hvm/viridian/viridian.c b/xen/arch/x86/hvm/viridian/viridian.c
index 54035f75cb1a..7871e425cbfe 100644
--- a/xen/arch/x86/hvm/viridian/viridian.c
+++ b/xen/arch/x86/hvm/viridian/viridian.c
@@ -518,6 +518,69 @@ static bool need_flush(void *ctxt, struct vcpu *v)
return vcpu_mask & (1ul << v->vcpu_id);
}

+union hypercall_input {
+ uint64_t raw;
+ struct {
+ uint16_t call_code;
+ uint16_t fast:1;
+ uint16_t rsvd1:15;
+ uint16_t rep_count:12;
+ uint16_t rsvd2:4;
+ uint16_t rep_start:12;
+ uint16_t rsvd3:4;
+ };
+};
+
+union hypercall_output {
+ uint64_t raw;
+ struct {
+ uint16_t result;
+ uint16_t rsvd1;
+ uint32_t rep_complete:12;
+ uint32_t rsvd2:20;
+ };
+};
+
+static int hvcall_flush(const union hypercall_input *input,
+ union hypercall_output *output,
+ paddr_t input_params_gpa,
+ paddr_t output_params_gpa)
+{
+ struct {
+ uint64_t address_space;
+ uint64_t flags;
+ uint64_t vcpu_mask;
+ } input_params;
+
+ /* These hypercalls should never use the fast-call convention. */
+ if ( input->fast )
+ return -EINVAL;
+
+ /* Get input parameters. */
+ if ( hvm_copy_from_guest_phys(&input_params, input_params_gpa,
+ sizeof(input_params)) != HVMTRANS_okay )
+ return -EINVAL;
+
+ /*
+ * It is not clear from the spec. if we are supposed to
+ * include current virtual CPU in the set or not in this case,
+ * so err on the safe side.
+ */
+ if ( input_params.flags & HV_FLUSH_ALL_PROCESSORS )
+ input_params.vcpu_mask = ~0ul;
+
+ /*
+ * A false return means that another vcpu is currently trying
+ * a similar operation, so back off.
+ */
+ if ( !paging_flush_tlb(need_flush, &input_params.vcpu_mask) )
+ return -ERESTART;
+
+ output->rep_complete = input->rep_count;
+
+ return 0;
+}
+
int viridian_hypercall(struct cpu_user_regs *regs)
{
struct vcpu *curr = current;
@@ -525,29 +588,8 @@ int viridian_hypercall(struct cpu_user_regs *regs)
int mode = hvm_guest_x86_mode(curr);
unsigned long input_params_gpa, output_params_gpa;
uint16_t status = HV_STATUS_SUCCESS;
-
- union hypercall_input {
- uint64_t raw;
- struct {
- uint16_t call_code;
- uint16_t fast:1;
- uint16_t rsvd1:15;
- uint16_t rep_count:12;
- uint16_t rsvd2:4;
- uint16_t rep_start:12;
- uint16_t rsvd3:4;
- };
- } input;
-
- union hypercall_output {
- uint64_t raw;
- struct {
- uint16_t result;
- uint16_t rsvd1;
- uint32_t rep_complete:12;
- uint32_t rsvd2:20;
- };
- } output = { 0 };
+ union hypercall_input input;
+ union hypercall_output output = {};

ASSERT(is_viridian_domain(currd));

@@ -580,41 +622,25 @@ int viridian_hypercall(struct cpu_user_regs *regs)
case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
{
- struct {
- uint64_t address_space;
- uint64_t flags;
- uint64_t vcpu_mask;
- } input_params;
+ int rc = hvcall_flush(&input, &output, input_params_gpa,
+ output_params_gpa);

- /* These hypercalls should never use the fast-call convention. */
- status = HV_STATUS_INVALID_PARAMETER;
- if ( input.fast )
+ switch ( rc )
+ {
+ case 0:
break;

- /* Get input parameters. */
- if ( hvm_copy_from_guest_phys(&input_params, input_params_gpa,
- sizeof(input_params)) !=
- HVMTRANS_okay )
- break;
-
- /*
- * It is not clear from the spec. if we are supposed to
- * include current virtual CPU in the set or not in this case,
- * so err on the safe side.
- */
- if ( input_params.flags & HV_FLUSH_ALL_PROCESSORS )
- input_params.vcpu_mask = ~0ul;
-
- /*
- * A false return means that another vcpu is currently trying
- * a similar operation, so back off.
- */
- if ( !paging_flush_tlb(need_flush, &input_params.vcpu_mask) )
+ case -ERESTART:
return HVM_HCALL_preempted;

- output.rep_complete = input.rep_count;
+ default:
+ ASSERT_UNREACHABLE();
+ /* Fallthrough */
+ case -EINVAL:
+ status = HV_STATUS_INVALID_PARAMETER;
+ break;
+ }

- status = HV_STATUS_SUCCESS;
break;
}

--
2.20.1