diff mbox series

[RFC,v2,15/22] i386/xen: implement HYPERVISOR_vcpu_op

Message ID 20221209095612.689243-16-dwmw2@infradead.org
State New
Headers show
Series Xen HVM support under KVM | expand

Commit Message

David Woodhouse Dec. 9, 2022, 9:56 a.m. UTC
From: Joao Martins <joao.m.martins@oracle.com>

This is simply when guest tries to register a vcpu_info
and since vcpu_info placement is optional in the minimum ABI
therefore we can just fail with -ENOSYS

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
 target/i386/xen.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

Comments

Durrant, Paul Dec. 12, 2022, 2:51 p.m. UTC | #1
On 09/12/2022 09:56, David Woodhouse wrote:
> From: Joao Martins <joao.m.martins@oracle.com>
> 
> This is simply when guest tries to register a vcpu_info
> and since vcpu_info placement is optional in the minimum ABI
> therefore we can just fail with -ENOSYS
> 
> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
> ---
>   target/i386/xen.c | 25 +++++++++++++++++++++++++
>   1 file changed, 25 insertions(+)
> 
> diff --git a/target/i386/xen.c b/target/i386/xen.c
> index 2847b4f864..9d1daadee1 100644
> --- a/target/i386/xen.c
> +++ b/target/i386/xen.c
> @@ -19,6 +19,7 @@
>   #include "standard-headers/xen/version.h"
>   #include "standard-headers/xen/memory.h"
>   #include "standard-headers/xen/hvm/hvm_op.h"
> +#include "standard-headers/xen/vcpu.h"
>   
>   static int kvm_gva_rw(CPUState *cs, uint64_t gva, void *_buf, size_t sz,
>                         bool is_write)
> @@ -194,6 +195,25 @@ static bool kvm_xen_hcall_hvm_op(struct kvm_xen_exit *exit,
>       }
>   }
>   
> +static bool kvm_xen_hcall_vcpu_op(struct kvm_xen_exit *exit, X86CPU *cpu,
> +                                  int cmd, int vcpu_id, uint64_t arg)
> +{
> +    int err;
> +
> +    switch (cmd) {
> +    case VCPUOP_register_vcpu_info:
> +        /* no vcpu info placement for now */
> +        err = -ENOSYS;

Again, should this patch be deferred until we actually implement 
something useful here? I.e. folding it into the subsequent patch? It's 
not like the boilerplate is massive.

   Paul
David Woodhouse Dec. 13, 2022, 12:10 a.m. UTC | #2
On Mon, 2022-12-12 at 14:51 +0000, Paul Durrant wrote:
> Again, should this patch be deferred until we actually implement 
> something useful here? I.e. folding it into the subsequent patch? It's 
> not like the boilerplate is massive.

That's how Joao did it; it seems sane enough to do bite-sized pieces so
I didn't change it. As I've been through and rebased/reworked it all
about ten times so far, it's been useful for it to be in small chunks.
diff mbox series

Patch

diff --git a/target/i386/xen.c b/target/i386/xen.c
index 2847b4f864..9d1daadee1 100644
--- a/target/i386/xen.c
+++ b/target/i386/xen.c
@@ -19,6 +19,7 @@ 
 #include "standard-headers/xen/version.h"
 #include "standard-headers/xen/memory.h"
 #include "standard-headers/xen/hvm/hvm_op.h"
+#include "standard-headers/xen/vcpu.h"
 
 static int kvm_gva_rw(CPUState *cs, uint64_t gva, void *_buf, size_t sz,
                       bool is_write)
@@ -194,6 +195,25 @@  static bool kvm_xen_hcall_hvm_op(struct kvm_xen_exit *exit,
     }
 }
 
+static bool kvm_xen_hcall_vcpu_op(struct kvm_xen_exit *exit, X86CPU *cpu,
+                                  int cmd, int vcpu_id, uint64_t arg)
+{
+    int err;
+
+    switch (cmd) {
+    case VCPUOP_register_vcpu_info:
+        /* no vcpu info placement for now */
+        err = -ENOSYS;
+        break;
+
+    default:
+        return false;
+    }
+
+    exit->u.hcall.result = err;
+    return true;
+}
+
 static bool __kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit)
 {
     uint16_t code = exit->u.hcall.input;
@@ -204,6 +224,11 @@  static bool __kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit)
     }
 
     switch (code) {
+    case __HYPERVISOR_vcpu_op:
+        return kvm_xen_hcall_vcpu_op(exit, cpu,
+                                     exit->u.hcall.params[0],
+                                     exit->u.hcall.params[1],
+                                     exit->u.hcall.params[2]);
     case __HYPERVISOR_hvm_op:
         return kvm_xen_hcall_hvm_op(exit, exit->u.hcall.params[0],
                                     exit->u.hcall.params[1]);