diff options
| author | Michael Kelley <mikelley@microsoft.com> | 2023-03-26 06:52:07 -0700 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2023-04-17 19:19:04 +0000 |
| commit | 2c6ba4216844ca7918289b49ed5f3f7138ee2402 (patch) | |
| tree | ddb51ac3aee357de90cc236adec1efacea267b57 /arch/x86/include/asm/hyperv-tlfs.h | |
| parent | 6afd9dc1a4b158456c072580f0851b4dbaaa02f1 (diff) | |
PCI: hv: Enable PCI pass-thru devices in Confidential VMs
For PCI pass-thru devices in a Confidential VM, Hyper-V requires
that PCI config space be accessed via hypercalls. In normal VMs,
config space accesses are trapped to the Hyper-V host and emulated.
But in a confidential VM, the host can't access guest memory to
decode the instruction for emulation, so an explicit hypercall must
be used.
Add functions to make the new MMIO read and MMIO write hypercalls.
Update the PCI config space access functions to use the hypercalls
when such use is indicated by Hyper-V flags. Also, set the flag to
allow the Hyper-V PCI driver to be loaded and used in a Confidential
VM (a.k.a., "Isolation VM"). The driver has previously been hardened
against a malicious Hyper-V host[1].
[1] https://lore.kernel.org/all/20220511223207.3386-2-parri.andrea@gmail.com/
Co-developed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Link: https://lore.kernel.org/r/1679838727-87310-13-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/hyperv-tlfs.h')
| -rw-r--r-- | arch/x86/include/asm/hyperv-tlfs.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h index 0b73a809e9e1..b4fb75bd1013 100644 --- a/arch/x86/include/asm/hyperv-tlfs.h +++ b/arch/x86/include/asm/hyperv-tlfs.h @@ -122,6 +122,9 @@ /* Recommend using enlightened VMCS */ #define HV_X64_ENLIGHTENED_VMCS_RECOMMENDED BIT(14) +/* Use hypercalls for MMIO config space access */ +#define HV_X64_USE_MMIO_HYPERCALLS BIT(21) + /* * CPU management features identification. * These are HYPERV_CPUID_CPU_MANAGEMENT_FEATURES.EAX bits. |