Re: [PATCH v13 29/30] LoongArch: KVM: Supplement kvm document about LoongArch-specific part

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




在 2023/6/16 上午10:59, Huacai Chen 写道:
On Fri, Jun 16, 2023 at 10:39 AM zhaotianrui <zhaotianrui@xxxxxxxxxxx> wrote:

在 2023/6/15 下午5:42, Huacai Chen 写道:
Hi, Tianrui,

On Fri, Jun 9, 2023 at 5:09 PM Tianrui Zhao <zhaotianrui@xxxxxxxxxxx> wrote:
Supplement kvm document about LoongArch-specific part, such as add
api introduction for GET/SET_ONE_REG, GET/SET_FPU, GET/SET_MP_STATE,
etc.

Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
---
   Documentation/virt/kvm/api.rst | 71 +++++++++++++++++++++++++++++-----
   1 file changed, 62 insertions(+), 9 deletions(-)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index add067793b90..ad8e13eab48d 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -416,6 +416,12 @@ Reads the general purpose registers from the vcpu.
          __u64 pc;
     };

+  /* LoongArch */
+  struct kvm_regs {
Add a " /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */" line as others here?
Thanks, I will add this comment here.

Tianrui Zhao

+        unsigned long gpr[32];
+        unsigned long pc;
+  };
+

   4.12 KVM_SET_REGS
   -----------------
@@ -506,7 +512,7 @@ translation mode.
   ------------------

   :Capability: basic
-:Architectures: x86, ppc, mips, riscv
+:Architectures: x86, ppc, mips, riscv, loongarch
   :Type: vcpu ioctl
   :Parameters: struct kvm_interrupt (in)
   :Returns: 0 on success, negative on failure.
@@ -592,6 +598,14 @@ b) KVM_INTERRUPT_UNSET

   This is an asynchronous vcpu ioctl and can be invoked from any thread.

+LOONGARCH:
+^^^^^^^^^^
+
+Queues an external interrupt to be injected into the virtual CPU. A negative
+interrupt number dequeues the interrupt.
+
+This is an asynchronous vcpu ioctl and can be invoked from any thread.
+

   4.17 KVM_DEBUG_GUEST
   --------------------
@@ -737,7 +751,7 @@ signal mask.
   ----------------

   :Capability: basic
-:Architectures: x86
+:Architectures: x86, loongarch
   :Type: vcpu ioctl
   :Parameters: struct kvm_fpu (out)
   :Returns: 0 on success, -1 on error
@@ -746,7 +760,7 @@ Reads the floating point state from the vcpu.

   ::

-  /* for KVM_GET_FPU and KVM_SET_FPU */
+  /* x86: for KVM_GET_FPU and KVM_SET_FPU */
     struct kvm_fpu {
          __u8  fpr[8][16];
          __u16 fcw;
@@ -761,12 +775,22 @@ Reads the floating point state from the vcpu.
          __u32 pad2;
     };

+  /* LoongArch: for KVM_GET_FPU and KVM_SET_FPU */
+  struct kvm_fpu {
+        __u32 fcsr;
+        __u32 none;
Maybe use pad1 as x86 is better.

Huacai
Thanks, this 'none' variable is meaningless, and I will remove it. As
this have already been removed in the actually kvm_fpu structure.
Why remove? I think it is for alignment, just like pad1 for x86.

Huacai

This 'none' variable is not for alignment but a unused register named vcsr in kvm_fpu, so I think it could be removed.

Tianrui Zhao

Tianrui Zhao

+        __u64 fcc;
+        struct kvm_fpureg {
+                __u64 val64[4];
+        }fpr[32];
+  };
+

   4.23 KVM_SET_FPU
   ----------------

   :Capability: basic
-:Architectures: x86
+:Architectures: x86, loongarch
   :Type: vcpu ioctl
   :Parameters: struct kvm_fpu (in)
   :Returns: 0 on success, -1 on error
@@ -775,7 +799,7 @@ Writes the floating point state to the vcpu.

   ::

-  /* for KVM_GET_FPU and KVM_SET_FPU */
+  /* x86: for KVM_GET_FPU and KVM_SET_FPU */
     struct kvm_fpu {
          __u8  fpr[8][16];
          __u16 fcw;
@@ -790,6 +814,16 @@ Writes the floating point state to the vcpu.
          __u32 pad2;
     };

+  /* LoongArch: for KVM_GET_FPU and KVM_SET_FPU */
+  struct kvm_fpu {
+        __u32 fcsr;
+        __u32 none;
I will also remove this 'none' variable.

Tianrui Zhao

+        __u64 fcc;
+        struct kvm_fpureg {
+                __u64 val64[4];
+        }fpr[32];
+  };
+

   4.24 KVM_CREATE_IRQCHIP
   -----------------------
@@ -1387,7 +1421,7 @@ documentation when it pops into existence).
   -------------------

   :Capability: KVM_CAP_ENABLE_CAP
-:Architectures: mips, ppc, s390, x86
+:Architectures: mips, ppc, s390, x86, loongarch
   :Type: vcpu ioctl
   :Parameters: struct kvm_enable_cap (in)
   :Returns: 0 on success; -1 on error
@@ -1442,7 +1476,7 @@ for vm-wide capabilities.
   ---------------------

   :Capability: KVM_CAP_MP_STATE
-:Architectures: x86, s390, arm64, riscv
+:Architectures: x86, s390, arm64, riscv, loongarch
   :Type: vcpu ioctl
   :Parameters: struct kvm_mp_state (out)
   :Returns: 0 on success; -1 on error
@@ -1460,7 +1494,7 @@ Possible values are:

      ==========================    ===============================================
      KVM_MP_STATE_RUNNABLE         the vcpu is currently running
-                                 [x86,arm64,riscv]
+                                 [x86,arm64,riscv,loongarch]
      KVM_MP_STATE_UNINITIALIZED    the vcpu is an application processor (AP)
                                    which has not yet received an INIT signal [x86]
      KVM_MP_STATE_INIT_RECEIVED    the vcpu has received an INIT signal, and is
@@ -1516,11 +1550,14 @@ For riscv:
   The only states that are valid are KVM_MP_STATE_STOPPED and
   KVM_MP_STATE_RUNNABLE which reflect if the vcpu is paused or not.

+On LoongArch, only the KVM_MP_STATE_RUNNABLE state is used to reflect
+whether the vcpu is runnable.
+
   4.39 KVM_SET_MP_STATE
   ---------------------

   :Capability: KVM_CAP_MP_STATE
-:Architectures: x86, s390, arm64, riscv
+:Architectures: x86, s390, arm64, riscv, loongarch
   :Type: vcpu ioctl
   :Parameters: struct kvm_mp_state (in)
   :Returns: 0 on success; -1 on error
@@ -1538,6 +1575,9 @@ For arm64/riscv:
   The only states that are valid are KVM_MP_STATE_STOPPED and
   KVM_MP_STATE_RUNNABLE which reflect if the vcpu should be paused or not.

+On LoongArch, only the KVM_MP_STATE_RUNNABLE state is used to reflect
+whether the vcpu is runnable.
+
   4.40 KVM_SET_IDENTITY_MAP_ADDR
   ------------------------------

@@ -2839,6 +2879,19 @@ Following are the RISC-V D-extension registers:
     0x8020 0000 0600 0020 fcsr      Floating point control and status register
   ======================= ========= =============================================

+LoongArch registers are mapped using the lower 32 bits. The upper 16 bits of
+that is the register group type.
+
+LoongArch csr registers are used to control guest cpu or get status of guest
+cpu, and they have the following id bit patterns::
+
+  0x9030 0000 0001 00 <reg:5> <sel:3>   (64-bit)
+
+LoongArch KVM control registers are used to implement some new defined functions
+such as set vcpu counter or reset vcpu, and they have the following id bit patterns::
+
+  0x9030 0000 0002 <reg:16>
+

   4.69 KVM_GET_ONE_REG
   --------------------
--
2.39.1






[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux