qemu-kvm/SOURCES/kvm-i386-tdx-Track-RAM-entries-for-TDX-VM.patch

224 lines
6.7 KiB
Diff

From c4a9204c7d8521c6fdc6b02b48db74ac109bcf09 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri, 18 Jul 2025 18:03:46 +0200
Subject: [PATCH 050/115] i386/tdx: Track RAM entries for TDX VM
RH-Author: Paolo Bonzini <pbonzini@redhat.com>
RH-MergeRequest: 391: TDX support, including attestation and device assignment
RH-Jira: RHEL-15710 RHEL-20798 RHEL-49728
RH-Acked-by: Yash Mankad <None>
RH-Acked-by: Peter Xu <peterx@redhat.com>
RH-Acked-by: David Hildenbrand <david@redhat.com>
RH-Commit: [50/115] fc14b8ad21b0be7179f9af62b6b32068122cae61 (bonzini/rhel-qemu-kvm)
The RAM of TDX VM can be classified into two types:
- TDX_RAM_UNACCEPTED: default type of TDX memory, which needs to be
accepted by TDX guest before it can be used and will be all-zeros
after being accepted.
- TDX_RAM_ADDED: the RAM that is ADD'ed to TD guest before running, and
can be used directly. E.g., TD HOB and TEMP MEM that needed by TDVF.
Maintain TdxRamEntries[] which grabs the initial RAM info from e820 table
and mark each RAM range as default type TDX_RAM_UNACCEPTED.
Then turn the range of TD HOB and TEMP MEM to TDX_RAM_ADDED since these
ranges will be ADD'ed before TD runs and no need to be accepted runtime.
The TdxRamEntries[] are later used to setup the memory TD resource HOB
that passes memory info from QEMU to TDVF.
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250508150002.689633-22-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit f18672e4cf91feed4b91ef85a264a500935a2865)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
target/i386/kvm/tdx.c | 109 ++++++++++++++++++++++++++++++++++++++++++
target/i386/kvm/tdx.h | 14 ++++++
2 files changed, 123 insertions(+)
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 95687e3a91..d1c7821347 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -18,6 +18,7 @@
#include "crypto/hash.h"
#include "sysemu/sysemu.h"
+#include "hw/i386/e820_memory_layout.h"
#include "hw/i386/tdvf.h"
#include "hw/i386/x86.h"
#include "kvm_i386.h"
@@ -146,11 +147,110 @@ void tdx_set_tdvf_region(MemoryRegion *tdvf_mr)
tdx_guest->tdvf_mr = tdvf_mr;
}
+static void tdx_add_ram_entry(uint64_t address, uint64_t length,
+ enum TdxRamType type)
+{
+ uint32_t nr_entries = tdx_guest->nr_ram_entries;
+ tdx_guest->ram_entries = g_renew(TdxRamEntry, tdx_guest->ram_entries,
+ nr_entries + 1);
+
+ tdx_guest->ram_entries[nr_entries].address = address;
+ tdx_guest->ram_entries[nr_entries].length = length;
+ tdx_guest->ram_entries[nr_entries].type = type;
+ tdx_guest->nr_ram_entries++;
+}
+
+static int tdx_accept_ram_range(uint64_t address, uint64_t length)
+{
+ uint64_t head_start, tail_start, head_length, tail_length;
+ uint64_t tmp_address, tmp_length;
+ TdxRamEntry *e;
+ int i = 0;
+
+ do {
+ if (i == tdx_guest->nr_ram_entries) {
+ return -1;
+ }
+
+ e = &tdx_guest->ram_entries[i++];
+ } while (address + length <= e->address || address >= e->address + e->length);
+
+ /*
+ * The to-be-accepted ram range must be fully contained by one
+ * RAM entry.
+ */
+ if (e->address > address ||
+ e->address + e->length < address + length) {
+ return -1;
+ }
+
+ if (e->type == TDX_RAM_ADDED) {
+ return 0;
+ }
+
+ tmp_address = e->address;
+ tmp_length = e->length;
+
+ e->address = address;
+ e->length = length;
+ e->type = TDX_RAM_ADDED;
+
+ head_length = address - tmp_address;
+ if (head_length > 0) {
+ head_start = tmp_address;
+ tdx_add_ram_entry(head_start, head_length, TDX_RAM_UNACCEPTED);
+ }
+
+ tail_start = address + length;
+ if (tail_start < tmp_address + tmp_length) {
+ tail_length = tmp_address + tmp_length - tail_start;
+ tdx_add_ram_entry(tail_start, tail_length, TDX_RAM_UNACCEPTED);
+ }
+
+ return 0;
+}
+
+static int tdx_ram_entry_compare(const void *lhs_, const void* rhs_)
+{
+ const TdxRamEntry *lhs = lhs_;
+ const TdxRamEntry *rhs = rhs_;
+
+ if (lhs->address == rhs->address) {
+ return 0;
+ }
+ if (le64_to_cpu(lhs->address) > le64_to_cpu(rhs->address)) {
+ return 1;
+ }
+ return -1;
+}
+
+static void tdx_init_ram_entries(void)
+{
+ unsigned i, j, nr_e820_entries;
+
+ nr_e820_entries = e820_get_table(NULL);
+ tdx_guest->ram_entries = g_new(TdxRamEntry, nr_e820_entries);
+
+ for (i = 0, j = 0; i < nr_e820_entries; i++) {
+ uint64_t addr, len;
+
+ if (e820_get_entry(i, E820_RAM, &addr, &len)) {
+ tdx_guest->ram_entries[j].address = addr;
+ tdx_guest->ram_entries[j].length = len;
+ tdx_guest->ram_entries[j].type = TDX_RAM_UNACCEPTED;
+ j++;
+ }
+ }
+ tdx_guest->nr_ram_entries = j;
+}
+
static void tdx_finalize_vm(Notifier *notifier, void *unused)
{
TdxFirmware *tdvf = &tdx_guest->tdvf;
TdxFirmwareEntry *entry;
+ tdx_init_ram_entries();
+
for_each_tdx_fw_entry(tdvf, entry) {
switch (entry->type) {
case TDVF_SECTION_TYPE_BFV:
@@ -166,12 +266,21 @@ static void tdx_finalize_vm(Notifier *notifier, void *unused)
entry->type);
exit(1);
}
+ if (tdx_accept_ram_range(entry->address, entry->size)) {
+ error_report("Failed to accept memory for TDVF section %d",
+ entry->type);
+ qemu_ram_munmap(-1, entry->mem_ptr, entry->size);
+ exit(1);
+ }
break;
default:
error_report("Unsupported TDVF section %d", entry->type);
exit(1);
}
}
+
+ qsort(tdx_guest->ram_entries, tdx_guest->nr_ram_entries,
+ sizeof(TdxRamEntry), &tdx_ram_entry_compare);
}
static Notifier tdx_machine_done_notify = {
diff --git a/target/i386/kvm/tdx.h b/target/i386/kvm/tdx.h
index 28a03c2a7b..36a7400e74 100644
--- a/target/i386/kvm/tdx.h
+++ b/target/i386/kvm/tdx.h
@@ -20,6 +20,17 @@ typedef struct TdxGuestClass {
/* TDX requires bus frequency 25MHz */
#define TDX_APIC_BUS_CYCLES_NS 40
+enum TdxRamType {
+ TDX_RAM_UNACCEPTED,
+ TDX_RAM_ADDED,
+};
+
+typedef struct TdxRamEntry {
+ uint64_t address;
+ uint64_t length;
+ enum TdxRamType type;
+} TdxRamEntry;
+
typedef struct TdxGuest {
X86ConfidentialGuest parent_obj;
@@ -34,6 +45,9 @@ typedef struct TdxGuest {
MemoryRegion *tdvf_mr;
TdxFirmware tdvf;
+
+ uint32_t nr_ram_entries;
+ TdxRamEntry *ram_entries;
} TdxGuest;
#ifdef CONFIG_TDX
--
2.50.1