diff options
| author | Bin Lu <bin.lu@arm.com> | 2020-05-15 05:28:46 -0400 |
|---|---|---|
| committer | Bin Lu <bin.lu@arm.com> | 2020-05-17 22:28:39 -0400 |
| commit | a534b2c65236201703096bb010f8d6b742f14c0d (patch) | |
| tree | 368cc715e613c7ebe93240cf66be5873aa1d32cc /pkg/sentry/platform/ring0 | |
| parent | 4502b73d008e7696adbf035926092590f2077706 (diff) | |
adding the VM-Exit method for Arm64
On amd64, it uses 'HLT' to leave the guest.
Unlike amd64, arm64 can only uses mmio_exit/psci to leave the guest.
So, I designed the HYPERCALL_VMEXIT to be compatible with amd64/arm64.
To keep it simple, I used the address of exception table as the
MMIO base address, so that I can trigger a MMIO-EXIT by forcibly writing this space.
Then, in host user space, I can calculate this address to find out
which hypercall.
Signed-off-by: Bin Lu <bin.lu@arm.com>
Diffstat (limited to 'pkg/sentry/platform/ring0')
| -rw-r--r-- | pkg/sentry/platform/ring0/entry_arm64.s | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/pkg/sentry/platform/ring0/entry_arm64.s b/pkg/sentry/platform/ring0/entry_arm64.s index db6465663..2bc5f3ecd 100644 --- a/pkg/sentry/platform/ring0/entry_arm64.s +++ b/pkg/sentry/platform/ring0/entry_arm64.s @@ -362,9 +362,17 @@ mmio_exit: MOVD R1, CPU_LAZY_VFP(RSV_REG) VFP_DISABLE - // MMIO_EXIT. - MOVD $0, R9 - MOVD R0, 0xffff000000001000(R9) + // Trigger MMIO_EXIT/_KVM_HYPERCALL_VMEXIT. + // + // To keep it simple, I used the address of exception table as the + // MMIO base address, so that I can trigger a MMIO-EXIT by forcibly writing + // a read-only space. + // Also, the length is engough to match a sufficient number of hypercall ID. + // Then, in host user space, I can calculate this address to find out + // which hypercall. + MRS VBAR_EL1, R9 + MOVD R0, 0x0(R9) + RET // HaltAndResume halts execution and point the pointer to the resume function. |